My Exchange Server migration experience has taken me through Exchange 4.0 –> Exchange 5.5 all the way to the more modern Exchange 2007/2010 –> Exchange 2013. One of the most important and often skipped steps is to perform backups of recently migrated mailboxes (in today’s case once the mailbox is on Exchange 2013). This is overlooked because of either time, resources, lack of planning, etc. In the end it is immaterial as to why, backups should be first priority once a mailbox is moved. Why? Well, let me lay out a scenario that recently happened to a customer of mine.
The Scenario
The customer was performing the migration themselves from Exchange Server 2007 SP3 to Exchange 2013 CU7. Smaller mailboxes, about 80% of the company, were moved over a weekend. During the migration, the engineer noticed what seemed to be strange connectivity issues with the SAN. The engineer then rebooted the SAN, after carefully shutting down all VMs that were using this as storage. When the SAN came back up he had all sorts of issues. The end of the storage for his Exchange 2013 storage was that everything was lost/corrupt and because he had just completed a migration, he had no backups for recovery.
The Solution
One solution to this problem provides for a cleaner restore of the Exchange 2013 database. The steps (briefly) are as follows:
- Rebuild Exchange Server 2013 using this TechNet Article
- Add the databases back and mount them
- Confirm the users have ‘blank’ mailboxes and can connect
- On Exchange 2007, dismount the databases, remove the Edb and associated files, and remount the databases
- Move users from Exchange 2013 to Exchange 2007
- Confirm again the mailboxes are blank and functional – but on Exchange 2007
- On Exchange 2007, dismount the databases, remove the Edb and associated files, and remount the databases
- Restore mailbox data to the Exchange 2007 Server
- Re-migrate mailboxes to Exchange 2013
- Backup Exchange 2013 databases
Conclusion
In short, backups are still important. Even during or right after a migration of mailboxes. Failing to perform this task can result in extended downtimes and end-user pain. Backups should be an integral part of backups.
