Upgrade Dovecot Cluster 2.2 to 2.3

Hi All

I’m planing to upgrade/migrate my dovecot cluster with two dovecot 2.2.36 nodes to 2.3.16. They use Maildir als IMAP backend and will continue to use that in the future.

Can I just:

• Install a new Server (AlmaLinux 9)
• Stop dovecot on the old node-2
• Copy all the data from the old mail directory of node-2 to the new one
• Install dovecot 2.3 on the new on with more or less the same config and let it run
• Repeat the same with old node-1 ?

Or would it be better to start of with an empty mail directory and let the other old node imapsync the data to the new one? - What would the advantage be (over the disadvantage that it may take some time to get everything synced)?

I know that Maildir are just static files, so moving them to the new server should not be a problem. I’m thinking more about indexes created by dovecot 2.2.36… Are they read without issues with the newever dovecot 2.3.16 or should I consider a re-index. or something the like?

thanks in advance, Steven

-- https://steven.varco.ch/ https://www.tech-island.com/