Andy Smith wrote: > Just as some free advice though… > > 1. I find it hard to believe you have more than 2000 Debian installs > without some sort of existing automation / configuration > management > > 2. Given (1), I would approach the task by learning your config > management and modifying it to deploy a Debian 12 version of each > kind of Debian 11 server you already have. > > 3. I'd then do a rolling deploy that slowly takes Debian 11 servers > out of service and re-provisions them as Debian 12. I would not > try to upgrade anything in place. Although Debian supports that, > at scale I find it harder to account for all variables than with > a clean install, and if you already have automation to deploy and > configure a host then an in-lace upgrade also takes longer in my > experience.
We do hundreds rather than thousands, but we do them: - with an existing configuration automation system (chef/cinc) - in-place upgrades - in tiers, where a given function (e.g. web servers) will have representative machines in each tier, starting with a very small proof-of-concept upgrade, followed by corrections; then a somewhat larger upgrade group, followed by all the rest of the machines. Automated monitoring, too. -dsr-
