Notes to Self About Debian Upgrade

I just attempted to upgrade a Linode VM from Debian 10 Buster to Debian 11 Bullseye, but the upgrade failed and the VM had to be restored from backup. Apparently I was naïve about the amount of changes, and embarrassingly unprepared for this amount of issues. These are some notes for myself, for next time. Some of these I really, really should have thought of.

Linode has their own Debian mirrors, two of which change name in Bullseye.

I can make a manual snapshot before upgrade, so that I don't have to restore from yesterday's backup.

MySQL 8.0 has an upgrade checker utility. This can be run at any time, giving ample time to prepare for found issues.

Make a copy of the my.cnf file before-hand the MySQL 8.0 configuration setup looks very different, at a glance. Maybe I'll try this upgrade on a completely different VM first.

I had a database/file backup for the forum on the server that's newer than the Linode VM backup, but was not prepared to restore this. I have it in case of catastrophic failure, in case we have to re-install everything on a new VM. It hadn't occurred to me that it might be used in a case like this. I'll research backup restoration procedures for XenForo, and possibly write a script for it.

I think that covers the extent of the issues I encountered. Better luck (well, preparation) next time!

Links

Basic upgrade instructions.

About the repo name change.

MySQL 8.0 upgrade checker.

-- CC0 ew0k, 2021-10-07