Like many in the CentOS community, I was caught with the need to migrate my enterprise servers from CentOS 8 to something else. Reading up on Rocky and AlmaLinux, I decided temporarily to convert to CentOS stream to get updates and prep for eventual final migration.
Now it’s time to say goodbye to CentOS (I’ll miss it). I can’t afford to be in a “forced” beta channel with a production system. I already have kernel modules not loading properly.
Converting to AlmaLinux, especially from a freshly updated CentOS stream 8 system looks simple enough. Any “gotcha’s” I should be aware before I take the plunge?
(I chose AlmaLinux because it is backed by a solid company not likely to do to us what CentOS did to us (i.e. sell out and not keep EOL as promised). Rocky looks good, but it is an individual who supports it. And I like the AlmaLinux logo better!)
pretty sure stream to alma is not supported as it would be downgrading packages. you shouldn’t have moved to stream, should have stuck to centos 8.5
I suspect as much since Stream tracks ahead. I didn’t realize it until too late. Looks like I will be stuck with Stream for awhile. A fresh install is not in the cards.
Perhaps there will be interest enough to help those on Stream to migrate over to AlmaLinux.
The CentOS Linux 8 → CentOS Stream 8 was something like:
dnf --disablerepo '*' --enablerepo=extras swap centos-linux-repos centos-stream-repos
That is: remove old distro repos, add new distro repos, and then reinstall installed packages from visible repos.
The migration script from CentOS Linux 8 to AlmaLinux does very similar opetations. The “alma-repos” is not in CentOS repo, like the centos-stream-repos was, and there are probably more packages that have to be replaced to get “alma” where there was “centos”.
The trick here is obviously that the distro-sync looks for same-or-newer, while installed Stream packages are often “newer” than content in Alma repos. One would have to downgrade some packages.
You could swap the repo definitions already. That way you won’t start to get from Stream repos packages that are “ahead of 8.6”. Downside is that some security issues could pop up and stay in limbo.