Curious about my apt-get update returns

Question

So I try to apt-get update on the regular when I am working in Terminal. Recently I have been running said command and getting a few errors at the end. Doesn't seem to effect my box to much of an extent but, how can I go about troubleshooting all of these issues that are being returned? See below:

W: Failed to fetch cdrom://elementary OS 0.3.1 _Freya_ - Stable amd64 (20150903)/dists/trusty/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
W: Failed to fetch cdrom://elementary OS 0.3.1 _Freya_ - Stable amd64 (20150903)/dists/trusty/restricted/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
W: Failed to fetch cdrom://elementary OS 0.3.1 _Freya_ - Stable amd64 (20150903)/dists/trusty/main/binary-i386/Packages  Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch cdrom://elementary OS 0.3.1 _Freya_ - Stable amd64 (20150903)/dists/trusty/restricted/binary-i386/Packages  Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
W: Failed to fetch htp://ppa.launchpad.net/ronmi/wallbox/ubuntu/dists/trusty/main/binary-amd64/Packages  404  Not Found
W: Failed to fetch htp://ppa.launchpad.net/ronmi/wallbox/ubuntu/dists/trusty/main/binary-i386/Packages  404  Not Found
W: Failed to fetch htp://ppa.launchpad.net/versable/elementary-update/ubuntu/dists/trusty/main/binary-amd64/Packages  404  Not Found
W: Failed to fetch htp://ppa.launchpad.net/versable/elementary-update/ubuntu/dists/trusty/main/binary-i386/Packages  404  Not Found
E: Some index files failed to download. They have been ignored, or old ones used instead.

Answer 1

Solution for your specific question:

Open Software & Updates -- > other software tab:

• Uncheck cd rom option.

• You have added two unsupported PPA's:

  ppa:ronmi/wallbox and

  ppa:versable/elementary-update.

  Removing those two will solve 404 error.

  

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More information (for your curiosity ;))

Failed to fetch cdrom....:

The reason for this error is that cdrom has been included as one of the the sources here.

And to fix this issue, we need to remove this from the list of software sources.

What are 404 errors:

The 404 or Not Found error message is an HTTP standard response code indicating that the client was able to communicate with a given server, but the server could not find what was requested.

The web site hosting server will typically generate a "404 Not Found" web page when a user attempts to follow a broken or dead link;

Reasons for these errors:

• A user has enabled a PPA software-source that no longer exists

• A user has manually typed in a new software source incorrectly

• A PPA was added, but the maintainer has subsequently deleted some/all of the PPA (like here)

To eleminate these errors:

Open software & updates -- > other software tab:

• To remove Failed to fetch cdrom:// error mesage: uncheck CD-ROM option.

  

• To remove 404 errors:

  • If the error is due to a PPA - usually unticking the similarly named PPA with the URL shown in the error message will resolve this.

  • If the 404 error was due to an additional repository that has been added to /etc/apt/sources.list then its easier to add # character to the start of the line to comment out the offending repository

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Answer 2

Check out the first line of each of them. Failed to fetch cdrom:// and Failed to fetch htp://ppa.launchpad.net. It means that apt is looking for updates at these URLs, but it's not able to get them for some reason.

The first 4 are looking for a CD and you probably don't have that CD mounted.

The last 4 are PPAs you've installed and it looks like the URL is misspelled.

You can manage your software sources by:

1. open up the applications menu and search for "Software & Updates"

2. Select the "Other" tab

3. Edit, Add, or Remove, or uncheck the offending sources