We have recently had an issue over a 3 day weekend where our backups did not run the following Tuesday and caused Exchange to stop mail flow since the Logs were not backed up. As a solution we would like to upgrade the current 146Gb mirror we have for Logs with a mirrored 600GB setup. We currently have 3 servers in a DAG so we would upgrade the offline servers first and then mount the mail-stores from the online server to one of the recently upgraded servers. The drive letter will remain the same as well. Are there any considerations when doing this?