I’ve been testing an upgrade path from 9.04 (Jaunty) to 10.04 (Lucid) via 9.10 (Karmic) for a while now when I realized that Karmic may be deleted from the normal mirrors and only available on old-releases server. Started to get nervous how will I upgrade now. Read on to find out…
Since I only upgraded from one release to the other while both releases were still supported or at least the one that I wanted to upgrade to was, do-release-upgrade was working and all I had to worry about is that all services will still work as expected after the upgrade. The Ubuntu web site is not as straight forward for me as one would expect, to find useful documentation you have to click a few before you end up on the right pages. Anyhow some fellah has written pages about how to upgrade from unsupported releases to other unsupported releases (https://help.ubuntu.com/community/EOLUpgrades, more specifically https://help.ubuntu.com/community/EOLUpgrades/Jaunty). Well, that is easy, isn’t it… Not really. As soon as you issue do-release-upgrade it starts to check for new releases and determines that Lucid is the next available (supported), which is one step too far ahead and tell you “An upgrade from ‘jaunty’ to ‘lucid’ is not supported with this tool.” Let’s see what my favourite search engine has to say about this. Some hits, none really clean, nor none that would explain officially why is this happening. I guess Ubuntu got somewhat out of sequence with itself because Karmic is flagged unsupported in the http://changelogs.ubuntu.com/meta-release file which the update manager checks to determine what you can upgrade to, yet Karmic is still available from archive.ubuntu.com… One site was suggesting to download this file, modify it by modifying Supported: 0 to 1 in it and uploading it to your web server, then pointing /etc/update-manager/meta-release to your website. Well, as I was messing with this I noticed that once I ran the update manager against the modified file it was not trying to upgrade to Lucid any more even after I restored /etc/update-manager/meta-release to it’s original state. So I started digging and figured out that the update manager downloads this file and caches it, so it’s enough to modify the file on the disk, which lives under /var/lib/update-manager. Not sure how update manager determines if there is a newer version, but for the moment this works. I believe some time in the future Karmic will be moved to old-releases when this procedure will be obsolete.