Why is apt-get update failing to fetch from Ubuntu Mirrors?
When I run apt-get update I am encountering the following:
W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/<distribution>/main/binary-amd64/Packages 404 Not Found
Why can't I update any further?
When you encounter these messages, it may be because your current version of Ubuntu has reached its "End of Life". You can reference the following links to determine if the version has reached its end of life, and to read more about upgrading to a newer version of the distribution:
For upgrading the Linode's distribution, however, I would recommend creating a new Linode and deploying the version of the operating system you want to deploy to and rebuild your Linode's stack. Once the software is installed, you can then transfer the data from your old Linode to the new one, then swap the IP addresses between the two Linodes.
I hope this helps!