In those case you better try to correct the issue even if providing a non-secure solution and later state what should be done ASAP to avoid possible exploits to compromise your outdated servers.
Commonly the first problem arises when you try to install a package in an old distro:
$ sudo apt-get install nfs-common Reading package lists... Done Building dependency tree Reading state information... Done Package nfs-common is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source E: Package 'nfs-common' has no installation candidateTo illustrate a possible "fix" with an example let us say you get the below error when trying to update an old maverick distro:
Err http://us.archive.ubuntu.com/ubuntu/ maverick-updates/main portmap amd64 6.0.0-2ubuntu1.1 404 Not Found [IP: 188.8.131.52 80]Maverick is not longer a supported release so it won't be found in the original servers. You need to look for them in the old-releases server so most likely the below will work:
sudo sed -i 's/us.archive.ubuntu.com/old-releases.ubuntu.com/g' /etc/apt/sources.listMost likely you will get then some key related issues like:
W: GPG error: http://old-releases.ubuntu.com maverick-security Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 40976EAF437D05B5Which you can solve with:
$ sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 40976EAF437D05B5Now you should be able to install that package which was missing in your old distribution. However let me state this once again, you should never rely on this procedure. You should always upgrade your distribution. To safely upgrade the distribution I believe automated server management in terms of recipes is the way to go.