How to backup the server?
Aside from the obvious image backup of the entire volume, what folders and files do i need to backup to replicate/migrate my openem setup to a new server?
Theopenem has a built in replication system, you should be able to add the new server to the com server list, configure it's storage, and then ensure the replication schedule is set up.
If you have a com server that is using an SMB server, and you want to change that SMB server out from under the com server, then you should be able to replicate the SMB data using whichever tools it's platform affords and then point the com server at the new SMB server.
The data in the storage location is file copy modules, images, and "Client Versions", I'm not yet familiar with the last one but the later two only change when you change them so you should be able to schedule around the replication. My client versions folder is empty, if yours is too then that is also solved.
As far as a proper "backup", I'm unclear if that's truly possible with Theopenem, since the data at the storage location is understood based on metadata in the database. I think the intent is that you will have 2 or more com servers and that will provide redundancy, just not any sort of snapshot functionality.