I'm working on a Tenant to Tenant migration. The source tenant does not have an on-prem exchange server (well, they do, but it's shut down, Exchange 2010, not up to date, all the bad things). I don't know if this is relevant, but it might be.
I did a CSV export of all user mailboxes, including ArchiveState. I found 3 users that had an ArchiveState of "active". So I naturally assumed only 3 users had an archive. Post migration, the customer says "Hey Raechel, this user says her archive wasn't migrated." Well Mr. Customer, she wasn't one of the 3 users that had an online archive. So do an export again, this time using the PropertySet "Archive" instead of just getting the ArchiveState attribute. There are 1905 users (out of about 4K) that have an archive GUID. I know that only 3 of those have an archive state of Active. The other 1902 have an archive state of "none". The majority of these don't even have an archive name. How does this even happen?
I have a theory. Microsoft Docs tells admins to enable online archives in the Security and Compliance Center. When in a syncing environment with the schema extended for exchange (even if it's an outdated schema), when you enable the online archive from the Exchange Admin center, you get an error that this is out of write scope and should be done on-prem. You DO NOT get that same error in the same environment from the Security and Compliance center. It just enables the online archive. Since the Exchange Server was shut down, I feel like this is what most likely happened. Would this also cause the ArchiveState to be "none" and the ArchiveName to be emtpy in Exchange Online?
Have I mentioned that I HATE that Microsoft Doc? I show my customers that this exists and then I tell them to NEVER do it, especially when they have an on-prem management server as it will cause all the errors. Using the Security and Compliance Center to enable online archives should not be how admins are told to enable the online archive for users.