Below are the steps to reseed a Database Copy via Exchange PowerShell. The database copy that needs to be reseeded is DB01 on the mailbox Server MBX04. We will use the server MBX03 that has a healthy database copy to perform the reseed.
1. Check to see if the problematic database copy has a failed and/or suspended status:
get-mailboxdatabasecopystatus DB01
2. If the database copy is already failed and/or suspended, you can skip this step. If the database copy you wish to reseed has a status of healthy, you must suspend the database copy:
suspend-mailboxdatabasecopy DB01MBX04
3. To reseed the mailbox database copy, run the following:
update-mailboxdatabasecopy DB01MBX04 -sourceserver MBX03 -DeleteExistingFiles
Ex-Shell 