Problem: Iâ€™m managing an Exchange 2010 server with roughly 210 mailboxes. Most of which arenâ€™t very big only a few hundred MBs or so and have them setup within two databases for organizational reasons. The main DB has 157 mailboxes and was a whopping 346GB!!! Which is way too big and is making my backups take up to 24 hours to backup the whole DB, along with the mailboxes and other files.
Solution: After much reading, I found out that the problem had to do with two things: 1. Most of these mailboxes were migrated from an Exchange 2003 server and there has been known cases that the Exchange 2010 server DB can be a little bloated. 2. I then created a new DB and moved about 50 mailboxes to that DB which created white space within it.
Some of my options were to defrag my Exchange database using Esutil but from what I gather, it is not recommended by Microsoft and I have to take the DB offline to do it. My other option and the best one was to create a new Exchange database and move all my mailboxes to there. I did that and the size of my new database is about 60GB! Much better than the 340GB before.
*Note â€“ When a mailbox is being moved, it will be unavailable during that time. The length depends on the size of the mailbox. Keep that in mind when moving large mailboxes. Also, make sure you do a full backup of the database after the move is done.
4.22.13: I had my old database dismounted for the entire weekend before I removed it. Just in caseâ€¦ So today I attempted to remove the old database and got the following error:
Exchange 2013 Database Removal Error: â€œThis mailbox database contains one or more mailboxesâ€
Below is a great article on how to address this problem so you can safely remove the database.