Best Strategy to Move from CentOS 7 to AlmaLinux 9?

[esindril (Elvin Alin Sindrilaru)]

Hi Patrick,

You must do the conversion before moving above version 5.2.0, since later on this not possible. You can read more about the changes from 5.1. to 5.2 in this post:

Important notes for the eos-5.2.0 release

The EOS 5.2.0 release will contain a series of changes that have long been advertised, therefore please make sure to carefully review the following points before deciding to update. We no longer support CentOS Stream. Server and client packages are available for CentOS7(el-7), Alma8(el-8), Alma9(el-9), and opportunistically some Fedora releases. There’s a strong dependency on XRootD 5.6.2 / eos-xrootd 5.6.2, providing critical client fixes and ZTN support over XRoot protocol. EOS now requires …

Therefore, probably a good upgrade path is to first do the conversion, then upgrade to 5.2.32. At this point you can do the OS upgrade everywhere keeping the EOS version to 5.2.32. Once this is done, you can do another round of upgrades enabling EOS_USER_MQ_ON_QDB=1 once you install the latest 5.3.29.

There should be no issues with QuarkDB as you upgrade, as long as you move in steps 5.1 → 5.2 → 5.3 and the upgrade should be done QuarkDB → MGM → FSTs.

Enjoy the holidays and let me know if you have any issues with the upgrade.

Cheers,
Elvin