Updating Ubuntu & understanding errors thrown by APTHow do I fix the GPG error “NO_PUBKEY”?How can I fix a 404 Error when using a PPA or updating my package lists?How can I fix apt error “W: Target Packages … is configured multiple times”?How do I restore the default repositories?How to fix apt: Signature by key uses weak digest algorithm (SHA1)?Failed to download repository information due to missing CDROMreprepro: Signature by key uses weak digest algorithm (SHA1)Error Updating: izx/askubuntu/ubuntu xenial Release' does not have a Release fileUbuntu 16.04 LTS - `apt update` stuck at `0% [Waiting for headers]`Can't install software from Software CenterNot all updates can be installed (missing packages)Updage Manager considers generic packages as untrusted packagesApt-get failed to fetch from Ubuntu server with error code 404Why does apt-get give me an “Unable to connect” error?“Unable to connect” error with apt-get: possible proxy?appstreamcli: AppStream system cache was updated, but problems were found: Metadata files have errors: /var/cache/app-info/xmls/fwupd.xmlGetting apt warnings when updating Ubuntu

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Updating Ubuntu & understanding errors thrown by APT


How do I fix the GPG error “NO_PUBKEY”?How can I fix a 404 Error when using a PPA or updating my package lists?How can I fix apt error “W: Target Packages … is configured multiple times”?How do I restore the default repositories?How to fix apt: Signature by key uses weak digest algorithm (SHA1)?Failed to download repository information due to missing CDROMreprepro: Signature by key uses weak digest algorithm (SHA1)Error Updating: izx/askubuntu/ubuntu xenial Release' does not have a Release fileUbuntu 16.04 LTS - `apt update` stuck at `0% [Waiting for headers]`Can't install software from Software CenterNot all updates can be installed (missing packages)Updage Manager considers generic packages as untrusted packagesApt-get failed to fetch from Ubuntu server with error code 404Why does apt-get give me an “Unable to connect” error?“Unable to connect” error with apt-get: possible proxy?appstreamcli: AppStream system cache was updated, but problems were found: Metadata files have errors: /var/cache/app-info/xmls/fwupd.xmlGetting apt warnings when updating Ubuntu






.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty
margin-bottom:0;









2


















I am new to Ubuntu but I recently started using Ubuntu on my laptop for almost everything.



I executed sudo apt-get update to update my system, but I do not understand the output. I don't know whether the output is normal or there are some errors that I need to address.



Ign:1 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial InRelease
Ign:2 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial Release
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Err:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
 Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:17 http://dl.google.com/linux/chrome/deb stable InRelease
Get:18 http://dl.google.com/linux/chrome/deb stable Release [1,189 B] 
Get:19 http://dl.google.com/linux/chrome/deb stable Release.gpg [819 B] 
Hit:20 http://ppa.launchpad.net/alessandro-strada/ppa/ubuntu xenial InRelease 
Get:21 http://dl.google.com/linux/chrome/deb stable/main amd64 Packages [1,407 B]
Hit:22 https://download.01.org/gfx/ubuntu/16.04/main xenial InRelease 
Ign:23 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial InRelease 
Get:24 http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease [18.1 kB]
Ign:24 http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease 
Hit:25 http://ppa.launchpad.net/noobslab/themes/ubuntu xenial InRelease 
Hit:26 http://ppa.launchpad.net/numix/ppa/ubuntu xenial InRelease 
Get:27 http://ppa.launchpad.net/papirus/papirus/ubuntu xenial InRelease [18.0 kB]
Hit:28 http://ppa.launchpad.net/snwh/pulp/ubuntu xenial InRelease 
Hit:29 http://ppa.launchpad.net/ubuntu-x-swat/updates/ubuntu xenial InRelease 
Hit:30 http://ppa.launchpad.net/webupd8team/atom/ubuntu xenial InRelease 
Hit:31 http://ppa.launchpad.net/webupd8team/java/ubuntu xenial InRelease 
Ign:32 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial Release 
Get:33 http://ppa.launchpad.net/papirus/papirus/ubuntu xenial/main amd64 Packages [2,496 B]
Get:34 http://ppa.launchpad.net/papirus/papirus/ubuntu xenial/main i386 Packages [2,496 B]
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Hit:42 http://archive.ubuntu.com/ubuntu xenial InRelease 
Hit:43 http://archive.canonical.com/ubuntu xenial InRelease 
Get:44 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [102 kB] 
Hit:45 http://archive.canonical.com xenial InRelease 
Ign:46 http://repo.vivaldi.com/stable/deb stable InRelease 
Hit:47 http://repo.vivaldi.com/stable/deb stable Release 
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Get:49 https://deb.nodesource.com/node_6.x xenial InRelease [4,634 B] 
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Get:50 http://archive.ubuntu.com/ubuntu xenial-backports InRelease [102 kB]
Hit:51 https://packages.microsoft.com/repos/vscode stable InRelease 
Hit:52 https://download.sublimetext.com apt/stable/ InRelease 
Get:53 https://deb.nodesource.com/node_6.x xenial/main amd64 Packages [1,003 B]
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Get:54 https://deb.nodesource.com/node_6.x xenial/main i386 Packages [1,001 B] 
Get:55 http://archive.ubuntu.com/ubuntu xenial-security InRelease [102 kB] 
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Hit:56 https://deb.opera.com/opera-stable stable InRelease 
Get:57 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages [678 kB]
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Get:58 https://packagecloud.io/slacktechnologies/slack/debian jessie InRelease [23.5 kB]
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Get:59 http://archive.ubuntu.com/ubuntu xenial-updates/main i386 Packages [637 kB]
Get:60 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 DEP-11 Metadata [307 kB]
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Get:61 http://archive.ubuntu.com/ubuntu xenial-updates/main DEP-11 64x64 Icons [213 kB]
Get:62 http://archive.ubuntu.com/ubuntu xenial-updates/universe amd64 Packages [564 kB]
Get:63 https://packagecloud.io/slacktechnologies/slack/debian jessie/main amd64 Packages [8,044 B]
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Get:64 http://archive.ubuntu.com/ubuntu xenial-updates/universe i386 Packages [529 kB]
Ign:65 https://packagecloud.io/slacktechnologies/slack/debian jessie/main i386 Packages
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Get:66 http://archive.ubuntu.com/ubuntu xenial-updates/universe amd64 DEP-11 Metadata [185 kB]
Get:67 http://archive.ubuntu.com/ubuntu xenial-updates/universe DEP-11 64x64 Icons [259 kB]
Get:65 https://packagecloud.io/slacktechnologies/slack/debian jessie/main i386 Packages [5,003 B]
Get:68 http://archive.ubuntu.com/ubuntu xenial-updates/multiverse amd64 DEP-11 Metadata [5,892 B]
Get:69 http://archive.ubuntu.com/ubuntu xenial-backports/main amd64 DEP-11 Metadata [3,328 B]
Get:70 http://archive.ubuntu.com/ubuntu xenial-backports/universe amd64 DEP-11 Metadata [4,676 B]
Get:71 http://archive.ubuntu.com/ubuntu xenial-security/main amd64 DEP-11 Metadata [62.5 kB]
Get:72 http://archive.ubuntu.com/ubuntu xenial-security/main DEP-11 64x64 Icons [62.6 kB]
Get:73 http://archive.ubuntu.com/ubuntu xenial-security/universe amd64 DEP-11 Metadata [51.4 kB]
Get:74 http://archive.ubuntu.com/ubuntu xenial-security/universe DEP-11 64x64 Icons [70.8 kB]
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Err:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages 
 404 Not Found
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages 
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages 
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US 
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en 
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata 
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons 
Fetched 4,027 kB in 16s (250 kB/s) 
Reading package lists... Done
W: Target Sources (main/source/Sources) is configured multiple times in /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:2 and /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:3
W: The repository 'cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: https://download.01.org/gfx/ubuntu/16.04/main/dists/xenial/InRelease: Signature by key 09D6EF97BFB38E916EF060E756A3DEF863961D39 uses weak digest algorithm (SHA1)
W: GPG error: http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7036069A2F22E44A
W: The repository 'http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: The repository 'http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: Failed to fetch cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2)/dists/xenial/main/binary-amd64/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
E: Failed to fetch http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu/dists/xenial/main/binary-amd64/Packages 404 Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.
W: Target Sources (main/source/Sources) is configured multiple times in /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:2 and /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:3


Update: After following suggestions provided by Zanna and suggestions from all the links included in her answer, my output is as follows:



sudo apt-get update
Hit:1 http://archive.canonical.com xenial InRelease 
Hit:2 http://archive.ubuntu.com/ubuntu xenial InRelease 
Hit:3 http://ppa.launchpad.net/alessandro-strada/ppa/ubuntu xenial InRelease
Get:4 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [102 kB] 
Hit:5 https://download.sublimetext.com apt/stable/ InRelease 
Hit:6 http://ppa.launchpad.net/noobslab/themes/ubuntu xenial InRelease 
Hit:7 https://deb.opera.com/opera-stable stable InRelease 
Hit:8 http://ppa.launchpad.net/numix/ppa/ubuntu xenial InRelease 
Get:9 http://archive.ubuntu.com/ubuntu xenial-backports InRelease [102 kB] 
Hit:10 http://ppa.launchpad.net/papirus/papirus/ubuntu xenial InRelease 
Hit:11 https://download.01.org/gfx/ubuntu/16.04/main xenial InRelease 
Hit:12 https://deb.nodesource.com/node_6.x xenial InRelease
Hit:13 https://packages.microsoft.com/repos/vscode stable InRelease
Hit:14 https://packagecloud.io/slacktechnologies/slack/debian jessie InRelease 
Get:15 http://archive.ubuntu.com/ubuntu xenial-security InRelease [102 kB] 
Hit:16 http://ppa.launchpad.net/snwh/pulp/ubuntu xenial InRelease 
Hit:17 http://ppa.launchpad.net/ubuntu-x-swat/updates/ubuntu xenial InRelease 
Hit:18 http://ppa.launchpad.net/ubuntuhandbook1/apps/ubuntu xenial InRelease 
Hit:19 http://ppa.launchpad.net/webupd8team/atom/ubuntu xenial InRelease 
Hit:20 http://ppa.launchpad.net/webupd8team/java/ubuntu xenial InRelease 
Fetched 306 kB in 5s (52.6 kB/s) 
Reading package lists... Done
W: https://download.01.org/gfx/ubuntu/16.04/main/dists/xenial/InRelease: Signature by key 09D6EF97BFB38E916EF060E756A3DEF863961D39 uses weak digest algorithm (SHA1)





16.04 apt package-management updates







share|improve this question






















  • 6





    The AskUbuntu format works best if you ask a single, specific question. Asking "What do these 8 warnings and 3 errors mean?" is 11 questions. Neither the question nor the answers are likely to help future users. Read each line that you don't understand carefully, then search AskUbuntu for key parts of the text - those warnings and errors have been explained before, multiple times. You have multiple problems, most (not all) caused by your PPAs, and each must be fixed separately...but all are quite easy to fix.

    – user535733
    Dec 9 '17 at 0:35







  • 2





    I don't think it makes sense to close this question as too broad. If hp1988 were to ask about those error messages individually, we would probably ask them to post the full output to give us a full picture of what is going on. And I disagree that it would not be helpful to explain all those errors in an answer. For one thing, they all relate to the same type of problem: outdated repositories.

    – Zanna
    Dec 10 '17 at 11:57






  • 1





    Possible duplicate of reprepro: Signature by key uses weak digest algorithm (SHA1)

    – karel
    Sep 19 at 13:18

















2


















I am new to Ubuntu but I recently started using Ubuntu on my laptop for almost everything.



I executed sudo apt-get update to update my system, but I do not understand the output. I don't know whether the output is normal or there are some errors that I need to address.



Ign:1 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial InRelease
Ign:2 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial Release
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Err:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
 Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:17 http://dl.google.com/linux/chrome/deb stable InRelease
Get:18 http://dl.google.com/linux/chrome/deb stable Release [1,189 B] 
Get:19 http://dl.google.com/linux/chrome/deb stable Release.gpg [819 B] 
Hit:20 http://ppa.launchpad.net/alessandro-strada/ppa/ubuntu xenial InRelease 
Get:21 http://dl.google.com/linux/chrome/deb stable/main amd64 Packages [1,407 B]
Hit:22 https://download.01.org/gfx/ubuntu/16.04/main xenial InRelease 
Ign:23 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial InRelease 
Get:24 http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease [18.1 kB]
Ign:24 http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease 
Hit:25 http://ppa.launchpad.net/noobslab/themes/ubuntu xenial InRelease 
Hit:26 http://ppa.launchpad.net/numix/ppa/ubuntu xenial InRelease 
Get:27 http://ppa.launchpad.net/papirus/papirus/ubuntu xenial InRelease [18.0 kB]
Hit:28 http://ppa.launchpad.net/snwh/pulp/ubuntu xenial InRelease 
Hit:29 http://ppa.launchpad.net/ubuntu-x-swat/updates/ubuntu xenial InRelease 
Hit:30 http://ppa.launchpad.net/webupd8team/atom/ubuntu xenial InRelease 
Hit:31 http://ppa.launchpad.net/webupd8team/java/ubuntu xenial InRelease 
Ign:32 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial Release 
Get:33 http://ppa.launchpad.net/papirus/papirus/ubuntu xenial/main amd64 Packages [2,496 B]
Get:34 http://ppa.launchpad.net/papirus/papirus/ubuntu xenial/main i386 Packages [2,496 B]
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Hit:42 http://archive.ubuntu.com/ubuntu xenial InRelease 
Hit:43 http://archive.canonical.com/ubuntu xenial InRelease 
Get:44 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [102 kB] 
Hit:45 http://archive.canonical.com xenial InRelease 
Ign:46 http://repo.vivaldi.com/stable/deb stable InRelease 
Hit:47 http://repo.vivaldi.com/stable/deb stable Release 
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Get:49 https://deb.nodesource.com/node_6.x xenial InRelease [4,634 B] 
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Get:50 http://archive.ubuntu.com/ubuntu xenial-backports InRelease [102 kB]
Hit:51 https://packages.microsoft.com/repos/vscode stable InRelease 
Hit:52 https://download.sublimetext.com apt/stable/ InRelease 
Get:53 https://deb.nodesource.com/node_6.x xenial/main amd64 Packages [1,003 B]
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Get:54 https://deb.nodesource.com/node_6.x xenial/main i386 Packages [1,001 B] 
Get:55 http://archive.ubuntu.com/ubuntu xenial-security InRelease [102 kB] 
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Hit:56 https://deb.opera.com/opera-stable stable InRelease 
Get:57 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages [678 kB]
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Get:58 https://packagecloud.io/slacktechnologies/slack/debian jessie InRelease [23.5 kB]
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Get:59 http://archive.ubuntu.com/ubuntu xenial-updates/main i386 Packages [637 kB]
Get:60 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 DEP-11 Metadata [307 kB]
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Get:61 http://archive.ubuntu.com/ubuntu xenial-updates/main DEP-11 64x64 Icons [213 kB]
Get:62 http://archive.ubuntu.com/ubuntu xenial-updates/universe amd64 Packages [564 kB]
Get:63 https://packagecloud.io/slacktechnologies/slack/debian jessie/main amd64 Packages [8,044 B]
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Get:64 http://archive.ubuntu.com/ubuntu xenial-updates/universe i386 Packages [529 kB]
Ign:65 https://packagecloud.io/slacktechnologies/slack/debian jessie/main i386 Packages
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Get:66 http://archive.ubuntu.com/ubuntu xenial-updates/universe amd64 DEP-11 Metadata [185 kB]
Get:67 http://archive.ubuntu.com/ubuntu xenial-updates/universe DEP-11 64x64 Icons [259 kB]
Get:65 https://packagecloud.io/slacktechnologies/slack/debian jessie/main i386 Packages [5,003 B]
Get:68 http://archive.ubuntu.com/ubuntu xenial-updates/multiverse amd64 DEP-11 Metadata [5,892 B]
Get:69 http://archive.ubuntu.com/ubuntu xenial-backports/main amd64 DEP-11 Metadata [3,328 B]
Get:70 http://archive.ubuntu.com/ubuntu xenial-backports/universe amd64 DEP-11 Metadata [4,676 B]
Get:71 http://archive.ubuntu.com/ubuntu xenial-security/main amd64 DEP-11 Metadata [62.5 kB]
Get:72 http://archive.ubuntu.com/ubuntu xenial-security/main DEP-11 64x64 Icons [62.6 kB]
Get:73 http://archive.ubuntu.com/ubuntu xenial-security/universe amd64 DEP-11 Metadata [51.4 kB]
Get:74 http://archive.ubuntu.com/ubuntu xenial-security/universe DEP-11 64x64 Icons [70.8 kB]
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Err:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages 
 404 Not Found
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages 
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages 
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US 
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en 
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata 
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons 
Fetched 4,027 kB in 16s (250 kB/s) 
Reading package lists... Done
W: Target Sources (main/source/Sources) is configured multiple times in /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:2 and /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:3
W: The repository 'cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: https://download.01.org/gfx/ubuntu/16.04/main/dists/xenial/InRelease: Signature by key 09D6EF97BFB38E916EF060E756A3DEF863961D39 uses weak digest algorithm (SHA1)
W: GPG error: http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7036069A2F22E44A
W: The repository 'http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: The repository 'http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: Failed to fetch cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2)/dists/xenial/main/binary-amd64/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
E: Failed to fetch http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu/dists/xenial/main/binary-amd64/Packages 404 Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.
W: Target Sources (main/source/Sources) is configured multiple times in /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:2 and /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:3


Update: After following suggestions provided by Zanna and suggestions from all the links included in her answer, my output is as follows:



sudo apt-get update
Hit:1 http://archive.canonical.com xenial InRelease 
Hit:2 http://archive.ubuntu.com/ubuntu xenial InRelease 
Hit:3 http://ppa.launchpad.net/alessandro-strada/ppa/ubuntu xenial InRelease
Get:4 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [102 kB] 
Hit:5 https://download.sublimetext.com apt/stable/ InRelease 
Hit:6 http://ppa.launchpad.net/noobslab/themes/ubuntu xenial InRelease 
Hit:7 https://deb.opera.com/opera-stable stable InRelease 
Hit:8 http://ppa.launchpad.net/numix/ppa/ubuntu xenial InRelease 
Get:9 http://archive.ubuntu.com/ubuntu xenial-backports InRelease [102 kB] 
Hit:10 http://ppa.launchpad.net/papirus/papirus/ubuntu xenial InRelease 
Hit:11 https://download.01.org/gfx/ubuntu/16.04/main xenial InRelease 
Hit:12 https://deb.nodesource.com/node_6.x xenial InRelease
Hit:13 https://packages.microsoft.com/repos/vscode stable InRelease
Hit:14 https://packagecloud.io/slacktechnologies/slack/debian jessie InRelease 
Get:15 http://archive.ubuntu.com/ubuntu xenial-security InRelease [102 kB] 
Hit:16 http://ppa.launchpad.net/snwh/pulp/ubuntu xenial InRelease 
Hit:17 http://ppa.launchpad.net/ubuntu-x-swat/updates/ubuntu xenial InRelease 
Hit:18 http://ppa.launchpad.net/ubuntuhandbook1/apps/ubuntu xenial InRelease 
Hit:19 http://ppa.launchpad.net/webupd8team/atom/ubuntu xenial InRelease 
Hit:20 http://ppa.launchpad.net/webupd8team/java/ubuntu xenial InRelease 
Fetched 306 kB in 5s (52.6 kB/s) 
Reading package lists... Done
W: https://download.01.org/gfx/ubuntu/16.04/main/dists/xenial/InRelease: Signature by key 09D6EF97BFB38E916EF060E756A3DEF863961D39 uses weak digest algorithm (SHA1)





16.04 apt package-management updates







share|improve this question






















  • 6





    The AskUbuntu format works best if you ask a single, specific question. Asking "What do these 8 warnings and 3 errors mean?" is 11 questions. Neither the question nor the answers are likely to help future users. Read each line that you don't understand carefully, then search AskUbuntu for key parts of the text - those warnings and errors have been explained before, multiple times. You have multiple problems, most (not all) caused by your PPAs, and each must be fixed separately...but all are quite easy to fix.

    – user535733
    Dec 9 '17 at 0:35







  • 2





    I don't think it makes sense to close this question as too broad. If hp1988 were to ask about those error messages individually, we would probably ask them to post the full output to give us a full picture of what is going on. And I disagree that it would not be helpful to explain all those errors in an answer. For one thing, they all relate to the same type of problem: outdated repositories.

    – Zanna
    Dec 10 '17 at 11:57






  • 1





    Possible duplicate of reprepro: Signature by key uses weak digest algorithm (SHA1)

    – karel
    Sep 19 at 13:18













2













2









2








I am new to Ubuntu but I recently started using Ubuntu on my laptop for almost everything.



I executed sudo apt-get update to update my system, but I do not understand the output. I don't know whether the output is normal or there are some errors that I need to address.



Ign:1 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial InRelease
Ign:2 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial Release
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Err:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
 Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:17 http://dl.google.com/linux/chrome/deb stable InRelease
Get:18 http://dl.google.com/linux/chrome/deb stable Release [1,189 B] 
Get:19 http://dl.google.com/linux/chrome/deb stable Release.gpg [819 B] 
Hit:20 http://ppa.launchpad.net/alessandro-strada/ppa/ubuntu xenial InRelease 
Get:21 http://dl.google.com/linux/chrome/deb stable/main amd64 Packages [1,407 B]
Hit:22 https://download.01.org/gfx/ubuntu/16.04/main xenial InRelease 
Ign:23 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial InRelease 
Get:24 http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease [18.1 kB]
Ign:24 http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease 
Hit:25 http://ppa.launchpad.net/noobslab/themes/ubuntu xenial InRelease 
Hit:26 http://ppa.launchpad.net/numix/ppa/ubuntu xenial InRelease 
Get:27 http://ppa.launchpad.net/papirus/papirus/ubuntu xenial InRelease [18.0 kB]
Hit:28 http://ppa.launchpad.net/snwh/pulp/ubuntu xenial InRelease 
Hit:29 http://ppa.launchpad.net/ubuntu-x-swat/updates/ubuntu xenial InRelease 
Hit:30 http://ppa.launchpad.net/webupd8team/atom/ubuntu xenial InRelease 
Hit:31 http://ppa.launchpad.net/webupd8team/java/ubuntu xenial InRelease 
Ign:32 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial Release 
Get:33 http://ppa.launchpad.net/papirus/papirus/ubuntu xenial/main amd64 Packages [2,496 B]
Get:34 http://ppa.launchpad.net/papirus/papirus/ubuntu xenial/main i386 Packages [2,496 B]
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Hit:42 http://archive.ubuntu.com/ubuntu xenial InRelease 
Hit:43 http://archive.canonical.com/ubuntu xenial InRelease 
Get:44 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [102 kB] 
Hit:45 http://archive.canonical.com xenial InRelease 
Ign:46 http://repo.vivaldi.com/stable/deb stable InRelease 
Hit:47 http://repo.vivaldi.com/stable/deb stable Release 
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Get:49 https://deb.nodesource.com/node_6.x xenial InRelease [4,634 B] 
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Get:50 http://archive.ubuntu.com/ubuntu xenial-backports InRelease [102 kB]
Hit:51 https://packages.microsoft.com/repos/vscode stable InRelease 
Hit:52 https://download.sublimetext.com apt/stable/ InRelease 
Get:53 https://deb.nodesource.com/node_6.x xenial/main amd64 Packages [1,003 B]
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Get:54 https://deb.nodesource.com/node_6.x xenial/main i386 Packages [1,001 B] 
Get:55 http://archive.ubuntu.com/ubuntu xenial-security InRelease [102 kB] 
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Hit:56 https://deb.opera.com/opera-stable stable InRelease 
Get:57 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages [678 kB]
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Get:58 https://packagecloud.io/slacktechnologies/slack/debian jessie InRelease [23.5 kB]
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Get:59 http://archive.ubuntu.com/ubuntu xenial-updates/main i386 Packages [637 kB]
Get:60 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 DEP-11 Metadata [307 kB]
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Get:61 http://archive.ubuntu.com/ubuntu xenial-updates/main DEP-11 64x64 Icons [213 kB]
Get:62 http://archive.ubuntu.com/ubuntu xenial-updates/universe amd64 Packages [564 kB]
Get:63 https://packagecloud.io/slacktechnologies/slack/debian jessie/main amd64 Packages [8,044 B]
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Get:64 http://archive.ubuntu.com/ubuntu xenial-updates/universe i386 Packages [529 kB]
Ign:65 https://packagecloud.io/slacktechnologies/slack/debian jessie/main i386 Packages
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Get:66 http://archive.ubuntu.com/ubuntu xenial-updates/universe amd64 DEP-11 Metadata [185 kB]
Get:67 http://archive.ubuntu.com/ubuntu xenial-updates/universe DEP-11 64x64 Icons [259 kB]
Get:65 https://packagecloud.io/slacktechnologies/slack/debian jessie/main i386 Packages [5,003 B]
Get:68 http://archive.ubuntu.com/ubuntu xenial-updates/multiverse amd64 DEP-11 Metadata [5,892 B]
Get:69 http://archive.ubuntu.com/ubuntu xenial-backports/main amd64 DEP-11 Metadata [3,328 B]
Get:70 http://archive.ubuntu.com/ubuntu xenial-backports/universe amd64 DEP-11 Metadata [4,676 B]
Get:71 http://archive.ubuntu.com/ubuntu xenial-security/main amd64 DEP-11 Metadata [62.5 kB]
Get:72 http://archive.ubuntu.com/ubuntu xenial-security/main DEP-11 64x64 Icons [62.6 kB]
Get:73 http://archive.ubuntu.com/ubuntu xenial-security/universe amd64 DEP-11 Metadata [51.4 kB]
Get:74 http://archive.ubuntu.com/ubuntu xenial-security/universe DEP-11 64x64 Icons [70.8 kB]
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Err:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages 
 404 Not Found
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages 
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages 
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US 
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en 
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata 
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons 
Fetched 4,027 kB in 16s (250 kB/s) 
Reading package lists... Done
W: Target Sources (main/source/Sources) is configured multiple times in /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:2 and /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:3
W: The repository 'cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: https://download.01.org/gfx/ubuntu/16.04/main/dists/xenial/InRelease: Signature by key 09D6EF97BFB38E916EF060E756A3DEF863961D39 uses weak digest algorithm (SHA1)
W: GPG error: http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7036069A2F22E44A
W: The repository 'http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: The repository 'http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: Failed to fetch cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2)/dists/xenial/main/binary-amd64/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
E: Failed to fetch http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu/dists/xenial/main/binary-amd64/Packages 404 Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.
W: Target Sources (main/source/Sources) is configured multiple times in /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:2 and /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:3


Update: After following suggestions provided by Zanna and suggestions from all the links included in her answer, my output is as follows:



sudo apt-get update
Hit:1 http://archive.canonical.com xenial InRelease 
Hit:2 http://archive.ubuntu.com/ubuntu xenial InRelease 
Hit:3 http://ppa.launchpad.net/alessandro-strada/ppa/ubuntu xenial InRelease
Get:4 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [102 kB] 
Hit:5 https://download.sublimetext.com apt/stable/ InRelease 
Hit:6 http://ppa.launchpad.net/noobslab/themes/ubuntu xenial InRelease 
Hit:7 https://deb.opera.com/opera-stable stable InRelease 
Hit:8 http://ppa.launchpad.net/numix/ppa/ubuntu xenial InRelease 
Get:9 http://archive.ubuntu.com/ubuntu xenial-backports InRelease [102 kB] 
Hit:10 http://ppa.launchpad.net/papirus/papirus/ubuntu xenial InRelease 
Hit:11 https://download.01.org/gfx/ubuntu/16.04/main xenial InRelease 
Hit:12 https://deb.nodesource.com/node_6.x xenial InRelease
Hit:13 https://packages.microsoft.com/repos/vscode stable InRelease
Hit:14 https://packagecloud.io/slacktechnologies/slack/debian jessie InRelease 
Get:15 http://archive.ubuntu.com/ubuntu xenial-security InRelease [102 kB] 
Hit:16 http://ppa.launchpad.net/snwh/pulp/ubuntu xenial InRelease 
Hit:17 http://ppa.launchpad.net/ubuntu-x-swat/updates/ubuntu xenial InRelease 
Hit:18 http://ppa.launchpad.net/ubuntuhandbook1/apps/ubuntu xenial InRelease 
Hit:19 http://ppa.launchpad.net/webupd8team/atom/ubuntu xenial InRelease 
Hit:20 http://ppa.launchpad.net/webupd8team/java/ubuntu xenial InRelease 
Fetched 306 kB in 5s (52.6 kB/s) 
Reading package lists... Done
W: https://download.01.org/gfx/ubuntu/16.04/main/dists/xenial/InRelease: Signature by key 09D6EF97BFB38E916EF060E756A3DEF863961D39 uses weak digest algorithm (SHA1)





16.04 apt package-management updates







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I am new to Ubuntu but I recently started using Ubuntu on my laptop for almost everything.



I executed sudo apt-get update to update my system, but I do not understand the output. I don't know whether the output is normal or there are some errors that I need to address.



Ign:1 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial InRelease
Ign:2 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial Release
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Ign:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:5 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main all Packages
Ign:6 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en_US
Ign:7 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main Translation-en
Ign:8 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 DEP-11 Metadata
Ign:9 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main DEP-11 64x64 Icons
Ign:10 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 Packages
Ign:11 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted i386 Packages
Ign:12 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted all Packages
Ign:13 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en_US
Ign:14 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted Translation-en
Ign:15 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted amd64 DEP-11 Metadata
Ign:16 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/restricted DEP-11 64x64 Icons
Err:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
 Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
Ign:4 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main i386 Packages
Ign:17 http://dl.google.com/linux/chrome/deb stable InRelease
Get:18 http://dl.google.com/linux/chrome/deb stable Release [1,189 B] 
Get:19 http://dl.google.com/linux/chrome/deb stable Release.gpg [819 B] 
Hit:20 http://ppa.launchpad.net/alessandro-strada/ppa/ubuntu xenial InRelease 
Get:21 http://dl.google.com/linux/chrome/deb stable/main amd64 Packages [1,407 B]
Hit:22 https://download.01.org/gfx/ubuntu/16.04/main xenial InRelease 
Ign:23 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial InRelease 
Get:24 http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease [18.1 kB]
Ign:24 http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease 
Hit:25 http://ppa.launchpad.net/noobslab/themes/ubuntu xenial InRelease 
Hit:26 http://ppa.launchpad.net/numix/ppa/ubuntu xenial InRelease 
Get:27 http://ppa.launchpad.net/papirus/papirus/ubuntu xenial InRelease [18.0 kB]
Hit:28 http://ppa.launchpad.net/snwh/pulp/ubuntu xenial InRelease 
Hit:29 http://ppa.launchpad.net/ubuntu-x-swat/updates/ubuntu xenial InRelease 
Hit:30 http://ppa.launchpad.net/webupd8team/atom/ubuntu xenial InRelease 
Hit:31 http://ppa.launchpad.net/webupd8team/java/ubuntu xenial InRelease 
Ign:32 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial Release 
Get:33 http://ppa.launchpad.net/papirus/papirus/ubuntu xenial/main amd64 Packages [2,496 B]
Get:34 http://ppa.launchpad.net/papirus/papirus/ubuntu xenial/main i386 Packages [2,496 B]
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Hit:42 http://archive.ubuntu.com/ubuntu xenial InRelease 
Hit:43 http://archive.canonical.com/ubuntu xenial InRelease 
Get:44 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [102 kB] 
Hit:45 http://archive.canonical.com xenial InRelease 
Ign:46 http://repo.vivaldi.com/stable/deb stable InRelease 
Hit:47 http://repo.vivaldi.com/stable/deb stable Release 
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Get:49 https://deb.nodesource.com/node_6.x xenial InRelease [4,634 B] 
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Get:50 http://archive.ubuntu.com/ubuntu xenial-backports InRelease [102 kB]
Hit:51 https://packages.microsoft.com/repos/vscode stable InRelease 
Hit:52 https://download.sublimetext.com apt/stable/ InRelease 
Get:53 https://deb.nodesource.com/node_6.x xenial/main amd64 Packages [1,003 B]
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Get:54 https://deb.nodesource.com/node_6.x xenial/main i386 Packages [1,001 B] 
Get:55 http://archive.ubuntu.com/ubuntu xenial-security InRelease [102 kB] 
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Hit:56 https://deb.opera.com/opera-stable stable InRelease 
Get:57 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages [678 kB]
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Get:58 https://packagecloud.io/slacktechnologies/slack/debian jessie InRelease [23.5 kB]
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Get:59 http://archive.ubuntu.com/ubuntu xenial-updates/main i386 Packages [637 kB]
Get:60 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 DEP-11 Metadata [307 kB]
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Get:61 http://archive.ubuntu.com/ubuntu xenial-updates/main DEP-11 64x64 Icons [213 kB]
Get:62 http://archive.ubuntu.com/ubuntu xenial-updates/universe amd64 Packages [564 kB]
Get:63 https://packagecloud.io/slacktechnologies/slack/debian jessie/main amd64 Packages [8,044 B]
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Get:64 http://archive.ubuntu.com/ubuntu xenial-updates/universe i386 Packages [529 kB]
Ign:65 https://packagecloud.io/slacktechnologies/slack/debian jessie/main i386 Packages
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Get:66 http://archive.ubuntu.com/ubuntu xenial-updates/universe amd64 DEP-11 Metadata [185 kB]
Get:67 http://archive.ubuntu.com/ubuntu xenial-updates/universe DEP-11 64x64 Icons [259 kB]
Get:65 https://packagecloud.io/slacktechnologies/slack/debian jessie/main i386 Packages [5,003 B]
Get:68 http://archive.ubuntu.com/ubuntu xenial-updates/multiverse amd64 DEP-11 Metadata [5,892 B]
Get:69 http://archive.ubuntu.com/ubuntu xenial-backports/main amd64 DEP-11 Metadata [3,328 B]
Get:70 http://archive.ubuntu.com/ubuntu xenial-backports/universe amd64 DEP-11 Metadata [4,676 B]
Get:71 http://archive.ubuntu.com/ubuntu xenial-security/main amd64 DEP-11 Metadata [62.5 kB]
Get:72 http://archive.ubuntu.com/ubuntu xenial-security/main DEP-11 64x64 Icons [62.6 kB]
Get:73 http://archive.ubuntu.com/ubuntu xenial-security/universe amd64 DEP-11 Metadata [51.4 kB]
Get:74 http://archive.ubuntu.com/ubuntu xenial-security/universe DEP-11 64x64 Icons [70.8 kB]
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Ign:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons
Err:35 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 Packages 
 404 Not Found
Ign:36 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main i386 Packages 
Ign:37 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main all Packages 
Ign:38 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en_US 
Ign:39 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main Translation-en 
Ign:40 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main amd64 DEP-11 Metadata 
Ign:41 http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial/main DEP-11 64x64 Icons 
Fetched 4,027 kB in 16s (250 kB/s) 
Reading package lists... Done
W: Target Sources (main/source/Sources) is configured multiple times in /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:2 and /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:3
W: The repository 'cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: https://download.01.org/gfx/ubuntu/16.04/main/dists/xenial/InRelease: Signature by key 09D6EF97BFB38E916EF060E756A3DEF863961D39 uses weak digest algorithm (SHA1)
W: GPG error: http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7036069A2F22E44A
W: The repository 'http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: The repository 'http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: Failed to fetch cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2)/dists/xenial/main/binary-amd64/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
E: Failed to fetch http://ppa.launchpad.net/gwibber-daily/ppa/ubuntu/dists/xenial/main/binary-amd64/Packages 404 Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.
W: Target Sources (main/source/Sources) is configured multiple times in /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:2 and /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:3


Update: After following suggestions provided by Zanna and suggestions from all the links included in her answer, my output is as follows:



sudo apt-get update
Hit:1 http://archive.canonical.com xenial InRelease 
Hit:2 http://archive.ubuntu.com/ubuntu xenial InRelease 
Hit:3 http://ppa.launchpad.net/alessandro-strada/ppa/ubuntu xenial InRelease
Get:4 http://archive.ubuntu.com/ubuntu xenial-updates InRelease [102 kB] 
Hit:5 https://download.sublimetext.com apt/stable/ InRelease 
Hit:6 http://ppa.launchpad.net/noobslab/themes/ubuntu xenial InRelease 
Hit:7 https://deb.opera.com/opera-stable stable InRelease 
Hit:8 http://ppa.launchpad.net/numix/ppa/ubuntu xenial InRelease 
Get:9 http://archive.ubuntu.com/ubuntu xenial-backports InRelease [102 kB] 
Hit:10 http://ppa.launchpad.net/papirus/papirus/ubuntu xenial InRelease 
Hit:11 https://download.01.org/gfx/ubuntu/16.04/main xenial InRelease 
Hit:12 https://deb.nodesource.com/node_6.x xenial InRelease
Hit:13 https://packages.microsoft.com/repos/vscode stable InRelease
Hit:14 https://packagecloud.io/slacktechnologies/slack/debian jessie InRelease 
Get:15 http://archive.ubuntu.com/ubuntu xenial-security InRelease [102 kB] 
Hit:16 http://ppa.launchpad.net/snwh/pulp/ubuntu xenial InRelease 
Hit:17 http://ppa.launchpad.net/ubuntu-x-swat/updates/ubuntu xenial InRelease 
Hit:18 http://ppa.launchpad.net/ubuntuhandbook1/apps/ubuntu xenial InRelease 
Hit:19 http://ppa.launchpad.net/webupd8team/atom/ubuntu xenial InRelease 
Hit:20 http://ppa.launchpad.net/webupd8team/java/ubuntu xenial InRelease 
Fetched 306 kB in 5s (52.6 kB/s) 
Reading package lists... Done
W: https://download.01.org/gfx/ubuntu/16.04/main/dists/xenial/InRelease: Signature by key 09D6EF97BFB38E916EF060E756A3DEF863961D39 uses weak digest algorithm (SHA1)





16.04 apt package-management updates




16.04 apt package-management updates






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edited Sep 24 at 8:36









Eliah Kagan

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asked Dec 8 '17 at 23:57









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  • 6





    The AskUbuntu format works best if you ask a single, specific question. Asking "What do these 8 warnings and 3 errors mean?" is 11 questions. Neither the question nor the answers are likely to help future users. Read each line that you don't understand carefully, then search AskUbuntu for key parts of the text - those warnings and errors have been explained before, multiple times. You have multiple problems, most (not all) caused by your PPAs, and each must be fixed separately...but all are quite easy to fix.

    – user535733
    Dec 9 '17 at 0:35







  • 2





    I don't think it makes sense to close this question as too broad. If hp1988 were to ask about those error messages individually, we would probably ask them to post the full output to give us a full picture of what is going on. And I disagree that it would not be helpful to explain all those errors in an answer. For one thing, they all relate to the same type of problem: outdated repositories.

    – Zanna
    Dec 10 '17 at 11:57






  • 1





    Possible duplicate of reprepro: Signature by key uses weak digest algorithm (SHA1)

    – karel
    Sep 19 at 13:18












  • 6





    The AskUbuntu format works best if you ask a single, specific question. Asking "What do these 8 warnings and 3 errors mean?" is 11 questions. Neither the question nor the answers are likely to help future users. Read each line that you don't understand carefully, then search AskUbuntu for key parts of the text - those warnings and errors have been explained before, multiple times. You have multiple problems, most (not all) caused by your PPAs, and each must be fixed separately...but all are quite easy to fix.

    – user535733
    Dec 9 '17 at 0:35







  • 2





    I don't think it makes sense to close this question as too broad. If hp1988 were to ask about those error messages individually, we would probably ask them to post the full output to give us a full picture of what is going on. And I disagree that it would not be helpful to explain all those errors in an answer. For one thing, they all relate to the same type of problem: outdated repositories.

    – Zanna
    Dec 10 '17 at 11:57






  • 1





    Possible duplicate of reprepro: Signature by key uses weak digest algorithm (SHA1)

    – karel
    Sep 19 at 13:18







6




6





The AskUbuntu format works best if you ask a single, specific question. Asking "What do these 8 warnings and 3 errors mean?" is 11 questions. Neither the question nor the answers are likely to help future users. Read each line that you don't understand carefully, then search AskUbuntu for key parts of the text - those warnings and errors have been explained before, multiple times. You have multiple problems, most (not all) caused by your PPAs, and each must be fixed separately...but all are quite easy to fix.

– user535733
Dec 9 '17 at 0:35






The AskUbuntu format works best if you ask a single, specific question. Asking "What do these 8 warnings and 3 errors mean?" is 11 questions. Neither the question nor the answers are likely to help future users. Read each line that you don't understand carefully, then search AskUbuntu for key parts of the text - those warnings and errors have been explained before, multiple times. You have multiple problems, most (not all) caused by your PPAs, and each must be fixed separately...but all are quite easy to fix.

– user535733
Dec 9 '17 at 0:35





2




2





I don't think it makes sense to close this question as too broad. If hp1988 were to ask about those error messages individually, we would probably ask them to post the full output to give us a full picture of what is going on. And I disagree that it would not be helpful to explain all those errors in an answer. For one thing, they all relate to the same type of problem: outdated repositories.

– Zanna
Dec 10 '17 at 11:57





I don't think it makes sense to close this question as too broad. If hp1988 were to ask about those error messages individually, we would probably ask them to post the full output to give us a full picture of what is going on. And I disagree that it would not be helpful to explain all those errors in an answer. For one thing, they all relate to the same type of problem: outdated repositories.

– Zanna
Dec 10 '17 at 11:57




1




1





Possible duplicate of reprepro: Signature by key uses weak digest algorithm (SHA1)

– karel
Sep 19 at 13:18





Possible duplicate of reprepro: Signature by key uses weak digest algorithm (SHA1)

– karel
Sep 19 at 13:18










1 Answer
1






active

oldest

votes


















2



















When you run sudo apt-get update, the APT program reads the file



/etc/apt/sources.list


and files in 



/etc/apt/sources.list.d/


and attempts to download index files from the repositories specified there to update the dpkg database on your system so that it contains accurate and current information about the contents of those repositories.



Errors thrown by APT often relate to the contents of these files.



The issues in your output all (apart from the weak digest algorithm warning) relate to repositories you cannot use on 16.04. This suggests that your repository listings are all misconfigured and that you should probably regenerate your sources from scratch! If you have only just installed Ubuntu, and you have never added a PPA, I suggest you delete all the files in /etc/apt/sources.list.d:



sudo rm /etc/apt/sources.list.d/*


Then use one of the methods described here How do I restore the default repositories? to set up your repositories cleanly.



However, to answer your question...



First you have a number of lines with



Ign: cdrom://Ubuntu [...]


Ign means that APT tried to download a file and could not find it at the given address, but not finding it was not important enough to prevent APT from continuing. This is not necessarily a problem. APT might just be checking for files that don't need to exist. A large number of Ign lines might indicate a problem though, as it suggests you have obsolete repositories configured, or a wrong configuration, because many requested files could not be found.



See:




  • How do Ign and Hit affect apt-get update? on Super User.

Then you got this related error:



Err:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs


which links to this warning and information:



W: The repository 'cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.


And this error:



E: Failed to fetch cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2)/dists/xenial/main/binary-amd64/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs


These messages are caused by a line in your /etc/apt/sources.list



deb cdrom [...]


This line should start with a # to cause it to be ignored, i.e. it should be "commented out". You can edit the sources.list file yourself, using a text editor opened with root privileges, e.g.:



sudo nano -w /etc/apt/sources.list


put a # in front of deb cdrom and save the file.



Or you can use the Software Sources GUI in Software and Updates.



After you have removed this repository, the Ign lines that mention cdrom should also disappear from your sudo apt-get update output.



See:



  • Failed to download repository information due to missing CDROM


  • the man page for apt-cdrom if you are interested in the rest of the error message

You also have many Ign lines relating to a PPA



Ign: http://ppa.launchpad.net/gwibber-daily


And some errors relating to it which are very similar to the cdrom errors. The gwibber-daily repository has not been updated for a very long time, and has no packages for your version of Ubuntu. You need to remove that PPA from your sources. PPA repository files are usually in /etc/apt/sources.list.d. You can get rid of the errors by deleting the file that relates to gwibber-daily from /etc/apt/sources.list.d, or again, by editing your sources from the GUI.



See:



  • How can I fix a 404 Error when using a PPA or updating my package lists?


  • Error Updating: izx/askubuntu/ubuntu xenial Release' does not have a Release file (I am looking for a better question/answer to link to - if any readers have a suggestion, please edit/comment)

You also have this warning:



W: Target Sources (main/source/Sources) is configured multiple times in /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:2 and /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:3


This means that the same repository is mentioned twice in your source configuration files. You can remove the error by deleting either (or both, if you don't want to use that repository) of the files mentioned, or in the Software Sources GUI.



See:



  • How can I automatically fix W: Target Packages ... is configured multiple times?

You also have



W: https://download.01.org/gfx/ubuntu/16.04/main/dists/xenial/InRelease: Signature by key 09D6EF97BFB38E916EF060E756A3DEF863961D39 uses weak digest algorithm (SHA1)


This is probably harmless; it just means the key used to sign the repository uses a less robust checksum method than APT's high standards expect. The repository does have a branch for 16.04, so you may not want to remove it. The warning will not prevent APT from downloading packages from that repository.



See:



  • How to fix apt: Signature by key uses weak digest algorithm (SHA1)?

Finally you have this well-known warning:



W: GPG error: http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7036069A2F22E44A
W: The repository 'http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.


It may sometimes be appropriate to solve this error by adding the key, but that would not solve the underlying problem, which is that, like the other repositories, this one has no packages for 16.04. You should remove this PPA from your sources too.






share|improve this answer



























  • Thank you so much @Zanna for taking time to answer my question. I really appreciate your efforts in explaining me about all the errors. I also visited links you provided for specific errors.After following your suggestions & suggestions provided in the links I managed to get the output (updated question with the new output) which is much more cleaner than what I used to have before.

    – hp8888
    Dec 10 '17 at 17:15












  • Zanna I still have one question at this point. After following all suggestions how do I make sure that I continue to receive Ubuntu 16.04 updates ? In other words , how do I verify that Ubuntu (Ubuntu OS & not third party s/w(s) such as chrome/opera etc) is updated when I execute sudo apt-get upgrade ?

    – hp8888
    Dec 10 '17 at 17:18











  • @hp1988 you're very welcome! You should always update before you upgrade. I suggest using sudo apt update rather than sudo apt-get update, because apt provides feedback, for example all packages are up to date or 2 packages can be upgraded, run 'apt list --upgradeable' to see them. The new output you posted looks healthy - the only possible concern is that you might have software that you installed, but then removed the repository for. Do you have any reason to believe that that is the case?

    – Zanna
    Dec 10 '17 at 17:26












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1 Answer
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1 Answer
1






active

oldest

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active

oldest

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active

oldest

votes









2



















When you run sudo apt-get update, the APT program reads the file



/etc/apt/sources.list


and files in 



/etc/apt/sources.list.d/


and attempts to download index files from the repositories specified there to update the dpkg database on your system so that it contains accurate and current information about the contents of those repositories.



Errors thrown by APT often relate to the contents of these files.



The issues in your output all (apart from the weak digest algorithm warning) relate to repositories you cannot use on 16.04. This suggests that your repository listings are all misconfigured and that you should probably regenerate your sources from scratch! If you have only just installed Ubuntu, and you have never added a PPA, I suggest you delete all the files in /etc/apt/sources.list.d:



sudo rm /etc/apt/sources.list.d/*


Then use one of the methods described here How do I restore the default repositories? to set up your repositories cleanly.



However, to answer your question...



First you have a number of lines with



Ign: cdrom://Ubuntu [...]


Ign means that APT tried to download a file and could not find it at the given address, but not finding it was not important enough to prevent APT from continuing. This is not necessarily a problem. APT might just be checking for files that don't need to exist. A large number of Ign lines might indicate a problem though, as it suggests you have obsolete repositories configured, or a wrong configuration, because many requested files could not be found.



See:




  • How do Ign and Hit affect apt-get update? on Super User.

Then you got this related error:



Err:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs


which links to this warning and information:



W: The repository 'cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.


And this error:



E: Failed to fetch cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2)/dists/xenial/main/binary-amd64/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs


These messages are caused by a line in your /etc/apt/sources.list



deb cdrom [...]


This line should start with a # to cause it to be ignored, i.e. it should be "commented out". You can edit the sources.list file yourself, using a text editor opened with root privileges, e.g.:



sudo nano -w /etc/apt/sources.list


put a # in front of deb cdrom and save the file.



Or you can use the Software Sources GUI in Software and Updates.



After you have removed this repository, the Ign lines that mention cdrom should also disappear from your sudo apt-get update output.



See:



  • Failed to download repository information due to missing CDROM


  • the man page for apt-cdrom if you are interested in the rest of the error message

You also have many Ign lines relating to a PPA



Ign: http://ppa.launchpad.net/gwibber-daily


And some errors relating to it which are very similar to the cdrom errors. The gwibber-daily repository has not been updated for a very long time, and has no packages for your version of Ubuntu. You need to remove that PPA from your sources. PPA repository files are usually in /etc/apt/sources.list.d. You can get rid of the errors by deleting the file that relates to gwibber-daily from /etc/apt/sources.list.d, or again, by editing your sources from the GUI.



See:



  • How can I fix a 404 Error when using a PPA or updating my package lists?


  • Error Updating: izx/askubuntu/ubuntu xenial Release' does not have a Release file (I am looking for a better question/answer to link to - if any readers have a suggestion, please edit/comment)

You also have this warning:



W: Target Sources (main/source/Sources) is configured multiple times in /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:2 and /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:3


This means that the same repository is mentioned twice in your source configuration files. You can remove the error by deleting either (or both, if you don't want to use that repository) of the files mentioned, or in the Software Sources GUI.



See:



  • How can I automatically fix W: Target Packages ... is configured multiple times?

You also have



W: https://download.01.org/gfx/ubuntu/16.04/main/dists/xenial/InRelease: Signature by key 09D6EF97BFB38E916EF060E756A3DEF863961D39 uses weak digest algorithm (SHA1)


This is probably harmless; it just means the key used to sign the repository uses a less robust checksum method than APT's high standards expect. The repository does have a branch for 16.04, so you may not want to remove it. The warning will not prevent APT from downloading packages from that repository.



See:



  • How to fix apt: Signature by key uses weak digest algorithm (SHA1)?

Finally you have this well-known warning:



W: GPG error: http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7036069A2F22E44A
W: The repository 'http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.


It may sometimes be appropriate to solve this error by adding the key, but that would not solve the underlying problem, which is that, like the other repositories, this one has no packages for 16.04. You should remove this PPA from your sources too.






share|improve this answer



























  • Thank you so much @Zanna for taking time to answer my question. I really appreciate your efforts in explaining me about all the errors. I also visited links you provided for specific errors.After following your suggestions & suggestions provided in the links I managed to get the output (updated question with the new output) which is much more cleaner than what I used to have before.

    – hp8888
    Dec 10 '17 at 17:15












  • Zanna I still have one question at this point. After following all suggestions how do I make sure that I continue to receive Ubuntu 16.04 updates ? In other words , how do I verify that Ubuntu (Ubuntu OS & not third party s/w(s) such as chrome/opera etc) is updated when I execute sudo apt-get upgrade ?

    – hp8888
    Dec 10 '17 at 17:18











  • @hp1988 you're very welcome! You should always update before you upgrade. I suggest using sudo apt update rather than sudo apt-get update, because apt provides feedback, for example all packages are up to date or 2 packages can be upgraded, run 'apt list --upgradeable' to see them. The new output you posted looks healthy - the only possible concern is that you might have software that you installed, but then removed the repository for. Do you have any reason to believe that that is the case?

    – Zanna
    Dec 10 '17 at 17:26















2



















When you run sudo apt-get update, the APT program reads the file



/etc/apt/sources.list


and files in 



/etc/apt/sources.list.d/


and attempts to download index files from the repositories specified there to update the dpkg database on your system so that it contains accurate and current information about the contents of those repositories.



Errors thrown by APT often relate to the contents of these files.



The issues in your output all (apart from the weak digest algorithm warning) relate to repositories you cannot use on 16.04. This suggests that your repository listings are all misconfigured and that you should probably regenerate your sources from scratch! If you have only just installed Ubuntu, and you have never added a PPA, I suggest you delete all the files in /etc/apt/sources.list.d:



sudo rm /etc/apt/sources.list.d/*


Then use one of the methods described here How do I restore the default repositories? to set up your repositories cleanly.



However, to answer your question...



First you have a number of lines with



Ign: cdrom://Ubuntu [...]


Ign means that APT tried to download a file and could not find it at the given address, but not finding it was not important enough to prevent APT from continuing. This is not necessarily a problem. APT might just be checking for files that don't need to exist. A large number of Ign lines might indicate a problem though, as it suggests you have obsolete repositories configured, or a wrong configuration, because many requested files could not be found.



See:




  • How do Ign and Hit affect apt-get update? on Super User.

Then you got this related error:



Err:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs


which links to this warning and information:



W: The repository 'cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.


And this error:



E: Failed to fetch cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2)/dists/xenial/main/binary-amd64/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs


These messages are caused by a line in your /etc/apt/sources.list



deb cdrom [...]


This line should start with a # to cause it to be ignored, i.e. it should be "commented out". You can edit the sources.list file yourself, using a text editor opened with root privileges, e.g.:



sudo nano -w /etc/apt/sources.list


put a # in front of deb cdrom and save the file.



Or you can use the Software Sources GUI in Software and Updates.



After you have removed this repository, the Ign lines that mention cdrom should also disappear from your sudo apt-get update output.



See:



  • Failed to download repository information due to missing CDROM


  • the man page for apt-cdrom if you are interested in the rest of the error message

You also have many Ign lines relating to a PPA



Ign: http://ppa.launchpad.net/gwibber-daily


And some errors relating to it which are very similar to the cdrom errors. The gwibber-daily repository has not been updated for a very long time, and has no packages for your version of Ubuntu. You need to remove that PPA from your sources. PPA repository files are usually in /etc/apt/sources.list.d. You can get rid of the errors by deleting the file that relates to gwibber-daily from /etc/apt/sources.list.d, or again, by editing your sources from the GUI.



See:



  • How can I fix a 404 Error when using a PPA or updating my package lists?


  • Error Updating: izx/askubuntu/ubuntu xenial Release' does not have a Release file (I am looking for a better question/answer to link to - if any readers have a suggestion, please edit/comment)

You also have this warning:



W: Target Sources (main/source/Sources) is configured multiple times in /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:2 and /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:3


This means that the same repository is mentioned twice in your source configuration files. You can remove the error by deleting either (or both, if you don't want to use that repository) of the files mentioned, or in the Software Sources GUI.



See:



  • How can I automatically fix W: Target Packages ... is configured multiple times?

You also have



W: https://download.01.org/gfx/ubuntu/16.04/main/dists/xenial/InRelease: Signature by key 09D6EF97BFB38E916EF060E756A3DEF863961D39 uses weak digest algorithm (SHA1)


This is probably harmless; it just means the key used to sign the repository uses a less robust checksum method than APT's high standards expect. The repository does have a branch for 16.04, so you may not want to remove it. The warning will not prevent APT from downloading packages from that repository.



See:



  • How to fix apt: Signature by key uses weak digest algorithm (SHA1)?

Finally you have this well-known warning:



W: GPG error: http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7036069A2F22E44A
W: The repository 'http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.


It may sometimes be appropriate to solve this error by adding the key, but that would not solve the underlying problem, which is that, like the other repositories, this one has no packages for 16.04. You should remove this PPA from your sources too.






share|improve this answer



























  • Thank you so much @Zanna for taking time to answer my question. I really appreciate your efforts in explaining me about all the errors. I also visited links you provided for specific errors.After following your suggestions & suggestions provided in the links I managed to get the output (updated question with the new output) which is much more cleaner than what I used to have before.

    – hp8888
    Dec 10 '17 at 17:15












  • Zanna I still have one question at this point. After following all suggestions how do I make sure that I continue to receive Ubuntu 16.04 updates ? In other words , how do I verify that Ubuntu (Ubuntu OS & not third party s/w(s) such as chrome/opera etc) is updated when I execute sudo apt-get upgrade ?

    – hp8888
    Dec 10 '17 at 17:18











  • @hp1988 you're very welcome! You should always update before you upgrade. I suggest using sudo apt update rather than sudo apt-get update, because apt provides feedback, for example all packages are up to date or 2 packages can be upgraded, run 'apt list --upgradeable' to see them. The new output you posted looks healthy - the only possible concern is that you might have software that you installed, but then removed the repository for. Do you have any reason to believe that that is the case?

    – Zanna
    Dec 10 '17 at 17:26













2















2











2









When you run sudo apt-get update, the APT program reads the file



/etc/apt/sources.list


and files in 



/etc/apt/sources.list.d/


and attempts to download index files from the repositories specified there to update the dpkg database on your system so that it contains accurate and current information about the contents of those repositories.



Errors thrown by APT often relate to the contents of these files.



The issues in your output all (apart from the weak digest algorithm warning) relate to repositories you cannot use on 16.04. This suggests that your repository listings are all misconfigured and that you should probably regenerate your sources from scratch! If you have only just installed Ubuntu, and you have never added a PPA, I suggest you delete all the files in /etc/apt/sources.list.d:



sudo rm /etc/apt/sources.list.d/*


Then use one of the methods described here How do I restore the default repositories? to set up your repositories cleanly.



However, to answer your question...



First you have a number of lines with



Ign: cdrom://Ubuntu [...]


Ign means that APT tried to download a file and could not find it at the given address, but not finding it was not important enough to prevent APT from continuing. This is not necessarily a problem. APT might just be checking for files that don't need to exist. A large number of Ign lines might indicate a problem though, as it suggests you have obsolete repositories configured, or a wrong configuration, because many requested files could not be found.



See:




  • How do Ign and Hit affect apt-get update? on Super User.

Then you got this related error:



Err:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs


which links to this warning and information:



W: The repository 'cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.


And this error:



E: Failed to fetch cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2)/dists/xenial/main/binary-amd64/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs


These messages are caused by a line in your /etc/apt/sources.list



deb cdrom [...]


This line should start with a # to cause it to be ignored, i.e. it should be "commented out". You can edit the sources.list file yourself, using a text editor opened with root privileges, e.g.:



sudo nano -w /etc/apt/sources.list


put a # in front of deb cdrom and save the file.



Or you can use the Software Sources GUI in Software and Updates.



After you have removed this repository, the Ign lines that mention cdrom should also disappear from your sudo apt-get update output.



See:



  • Failed to download repository information due to missing CDROM


  • the man page for apt-cdrom if you are interested in the rest of the error message

You also have many Ign lines relating to a PPA



Ign: http://ppa.launchpad.net/gwibber-daily


And some errors relating to it which are very similar to the cdrom errors. The gwibber-daily repository has not been updated for a very long time, and has no packages for your version of Ubuntu. You need to remove that PPA from your sources. PPA repository files are usually in /etc/apt/sources.list.d. You can get rid of the errors by deleting the file that relates to gwibber-daily from /etc/apt/sources.list.d, or again, by editing your sources from the GUI.



See:



  • How can I fix a 404 Error when using a PPA or updating my package lists?


  • Error Updating: izx/askubuntu/ubuntu xenial Release' does not have a Release file (I am looking for a better question/answer to link to - if any readers have a suggestion, please edit/comment)

You also have this warning:



W: Target Sources (main/source/Sources) is configured multiple times in /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:2 and /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:3


This means that the same repository is mentioned twice in your source configuration files. You can remove the error by deleting either (or both, if you don't want to use that repository) of the files mentioned, or in the Software Sources GUI.



See:



  • How can I automatically fix W: Target Packages ... is configured multiple times?

You also have



W: https://download.01.org/gfx/ubuntu/16.04/main/dists/xenial/InRelease: Signature by key 09D6EF97BFB38E916EF060E756A3DEF863961D39 uses weak digest algorithm (SHA1)


This is probably harmless; it just means the key used to sign the repository uses a less robust checksum method than APT's high standards expect. The repository does have a branch for 16.04, so you may not want to remove it. The warning will not prevent APT from downloading packages from that repository.



See:



  • How to fix apt: Signature by key uses weak digest algorithm (SHA1)?

Finally you have this well-known warning:



W: GPG error: http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7036069A2F22E44A
W: The repository 'http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.


It may sometimes be appropriate to solve this error by adding the key, but that would not solve the underlying problem, which is that, like the other repositories, this one has no packages for 16.04. You should remove this PPA from your sources too.






share|improve this answer
















When you run sudo apt-get update, the APT program reads the file



/etc/apt/sources.list


and files in 



/etc/apt/sources.list.d/


and attempts to download index files from the repositories specified there to update the dpkg database on your system so that it contains accurate and current information about the contents of those repositories.



Errors thrown by APT often relate to the contents of these files.



The issues in your output all (apart from the weak digest algorithm warning) relate to repositories you cannot use on 16.04. This suggests that your repository listings are all misconfigured and that you should probably regenerate your sources from scratch! If you have only just installed Ubuntu, and you have never added a PPA, I suggest you delete all the files in /etc/apt/sources.list.d:



sudo rm /etc/apt/sources.list.d/*


Then use one of the methods described here How do I restore the default repositories? to set up your repositories cleanly.



However, to answer your question...



First you have a number of lines with



Ign: cdrom://Ubuntu [...]


Ign means that APT tried to download a file and could not find it at the given address, but not finding it was not important enough to prevent APT from continuing. This is not necessarily a problem. APT might just be checking for files that don't need to exist. A large number of Ign lines might indicate a problem though, as it suggests you have obsolete repositories configured, or a wrong configuration, because many requested files could not be found.



See:




  • How do Ign and Hit affect apt-get update? on Super User.

Then you got this related error:



Err:3 cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial/main amd64 Packages
Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs


which links to this warning and information:



W: The repository 'cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2) xenial Release' does not have a Release file.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.


And this error:



E: Failed to fetch cdrom://Ubuntu 16.04.2 LTS _Xenial Xerus_ - Release amd64 (20170215.2)/dists/xenial/main/binary-amd64/Packages Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs


These messages are caused by a line in your /etc/apt/sources.list



deb cdrom [...]


This line should start with a # to cause it to be ignored, i.e. it should be "commented out". You can edit the sources.list file yourself, using a text editor opened with root privileges, e.g.:



sudo nano -w /etc/apt/sources.list


put a # in front of deb cdrom and save the file.



Or you can use the Software Sources GUI in Software and Updates.



After you have removed this repository, the Ign lines that mention cdrom should also disappear from your sudo apt-get update output.



See:



  • Failed to download repository information due to missing CDROM


  • the man page for apt-cdrom if you are interested in the rest of the error message

You also have many Ign lines relating to a PPA



Ign: http://ppa.launchpad.net/gwibber-daily


And some errors relating to it which are very similar to the cdrom errors. The gwibber-daily repository has not been updated for a very long time, and has no packages for your version of Ubuntu. You need to remove that PPA from your sources. PPA repository files are usually in /etc/apt/sources.list.d. You can get rid of the errors by deleting the file that relates to gwibber-daily from /etc/apt/sources.list.d, or again, by editing your sources from the GUI.



See:



  • How can I fix a 404 Error when using a PPA or updating my package lists?


  • Error Updating: izx/askubuntu/ubuntu xenial Release' does not have a Release file (I am looking for a better question/answer to link to - if any readers have a suggestion, please edit/comment)

You also have this warning:



W: Target Sources (main/source/Sources) is configured multiple times in /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:2 and /etc/apt/sources.list.d/ubuntu-x-swat-ubuntu-updates-xenial.list:3


This means that the same repository is mentioned twice in your source configuration files. You can remove the error by deleting either (or both, if you don't want to use that repository) of the files mentioned, or in the Software Sources GUI.



See:



  • How can I automatically fix W: Target Packages ... is configured multiple times?

You also have



W: https://download.01.org/gfx/ubuntu/16.04/main/dists/xenial/InRelease: Signature by key 09D6EF97BFB38E916EF060E756A3DEF863961D39 uses weak digest algorithm (SHA1)


This is probably harmless; it just means the key used to sign the repository uses a less robust checksum method than APT's high standards expect. The repository does have a branch for 16.04, so you may not want to remove it. The warning will not prevent APT from downloading packages from that repository.



See:



  • How to fix apt: Signature by key uses weak digest algorithm (SHA1)?

Finally you have this well-known warning:



W: GPG error: http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7036069A2F22E44A
W: The repository 'http://ppa.launchpad.net/hanipouspilot/rtlwifi/ubuntu xenial InRelease' is not signed.
N: Data from such a repository can't be authenticated and is therefore potentially dangerous to use.
N: See apt-secure(8) manpage for repository creation and user configuration details.


It may sometimes be appropriate to solve this error by adding the key, but that would not solve the underlying problem, which is that, like the other repositories, this one has no packages for 16.04. You should remove this PPA from your sources too.







share|improve this answer















share|improve this answer




share|improve this answer








edited Dec 10 '17 at 17:50









Eliah Kagan

96k25 gold badges256 silver badges413 bronze badges




96k25 gold badges256 silver badges413 bronze badges










answered Dec 10 '17 at 11:17









ZannaZanna

55.6k15 gold badges152 silver badges256 bronze badges




55.6k15 gold badges152 silver badges256 bronze badges















  • Thank you so much @Zanna for taking time to answer my question. I really appreciate your efforts in explaining me about all the errors. I also visited links you provided for specific errors.After following your suggestions & suggestions provided in the links I managed to get the output (updated question with the new output) which is much more cleaner than what I used to have before.

    – hp8888
    Dec 10 '17 at 17:15












  • Zanna I still have one question at this point. After following all suggestions how do I make sure that I continue to receive Ubuntu 16.04 updates ? In other words , how do I verify that Ubuntu (Ubuntu OS & not third party s/w(s) such as chrome/opera etc) is updated when I execute sudo apt-get upgrade ?

    – hp8888
    Dec 10 '17 at 17:18











  • @hp1988 you're very welcome! You should always update before you upgrade. I suggest using sudo apt update rather than sudo apt-get update, because apt provides feedback, for example all packages are up to date or 2 packages can be upgraded, run 'apt list --upgradeable' to see them. The new output you posted looks healthy - the only possible concern is that you might have software that you installed, but then removed the repository for. Do you have any reason to believe that that is the case?

    – Zanna
    Dec 10 '17 at 17:26

















  • Thank you so much @Zanna for taking time to answer my question. I really appreciate your efforts in explaining me about all the errors. I also visited links you provided for specific errors.After following your suggestions & suggestions provided in the links I managed to get the output (updated question with the new output) which is much more cleaner than what I used to have before.

    – hp8888
    Dec 10 '17 at 17:15












  • Zanna I still have one question at this point. After following all suggestions how do I make sure that I continue to receive Ubuntu 16.04 updates ? In other words , how do I verify that Ubuntu (Ubuntu OS & not third party s/w(s) such as chrome/opera etc) is updated when I execute sudo apt-get upgrade ?

    – hp8888
    Dec 10 '17 at 17:18











  • @hp1988 you're very welcome! You should always update before you upgrade. I suggest using sudo apt update rather than sudo apt-get update, because apt provides feedback, for example all packages are up to date or 2 packages can be upgraded, run 'apt list --upgradeable' to see them. The new output you posted looks healthy - the only possible concern is that you might have software that you installed, but then removed the repository for. Do you have any reason to believe that that is the case?

    – Zanna
    Dec 10 '17 at 17:26
















Thank you so much @Zanna for taking time to answer my question. I really appreciate your efforts in explaining me about all the errors. I also visited links you provided for specific errors.After following your suggestions & suggestions provided in the links I managed to get the output (updated question with the new output) which is much more cleaner than what I used to have before.

– hp8888
Dec 10 '17 at 17:15






Thank you so much @Zanna for taking time to answer my question. I really appreciate your efforts in explaining me about all the errors. I also visited links you provided for specific errors.After following your suggestions & suggestions provided in the links I managed to get the output (updated question with the new output) which is much more cleaner than what I used to have before.

– hp8888
Dec 10 '17 at 17:15














Zanna I still have one question at this point. After following all suggestions how do I make sure that I continue to receive Ubuntu 16.04 updates ? In other words , how do I verify that Ubuntu (Ubuntu OS & not third party s/w(s) such as chrome/opera etc) is updated when I execute sudo apt-get upgrade ?

– hp8888
Dec 10 '17 at 17:18





Zanna I still have one question at this point. After following all suggestions how do I make sure that I continue to receive Ubuntu 16.04 updates ? In other words , how do I verify that Ubuntu (Ubuntu OS & not third party s/w(s) such as chrome/opera etc) is updated when I execute sudo apt-get upgrade ?

– hp8888
Dec 10 '17 at 17:18













@hp1988 you're very welcome! You should always update before you upgrade. I suggest using sudo apt update rather than sudo apt-get update, because apt provides feedback, for example all packages are up to date or 2 packages can be upgraded, run 'apt list --upgradeable' to see them. The new output you posted looks healthy - the only possible concern is that you might have software that you installed, but then removed the repository for. Do you have any reason to believe that that is the case?

– Zanna
Dec 10 '17 at 17:26





@hp1988 you're very welcome! You should always update before you upgrade. I suggest using sudo apt update rather than sudo apt-get update, because apt provides feedback, for example all packages are up to date or 2 packages can be upgraded, run 'apt list --upgradeable' to see them. The new output you posted looks healthy - the only possible concern is that you might have software that you installed, but then removed the repository for. Do you have any reason to believe that that is the case?

– Zanna
Dec 10 '17 at 17:26


















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