Notes

I once visited a trainig course for Microsoft Exchange where the teacher said that you can defrag an Exchange database by simpling removing a DAG copy and then reseed it. This sounded much better than offline defrag, where you have to take the database offline.

It sounds logical, but it doesn't work. I tried it using a database that has no mailboxes anymore (I previously used that database for a forest migration), Get-MailboxDatabase showed that there was a lot of free space (AvailableNewMailboxSpace). I reseeded the database using Update-MailboxDatabaseCopy. But the reseeded copy had the same size as the original.

Nice idea, but it doesn't work.