DRBD Sync - Which folders need to be synced?

Hi,

I would like to upgrade my single Gitlab instance to a little drbd cluster with two servers.

I created the drbd on the server and the sync looks fine. The Folder which is now synced is: /var/opt/gitlab/.

But the question is, which folders I must sync on a update from Gitlab (What is the expiration in a version jump of Gitlab)?

Greetings
Alex