Hi, We have two mailbox servers in a DAG. Servers are running out of space and I am planning on moving databse files to SAN storages. I am unsure what speps should be taken. Do I need to remove DAG, move databases and build a new DAG again, or I can make database copies on server A active, move databases on server B, make server B active and then move server A. Any comment is appreciated.

You'll have to remove all mailbox database copies for the database being moved. However, you will keep them and later on move the passive copy of the mailbox database and its log stream to the new location. Each Mailbox server that will host a mailbox database copy, requires the same path. Here are the detailed steps: Move the Mailbox Database Path for a Mailbox Database Copy http://technet.microsoft.com/en-us/library/dd979782.aspxMCTS: Messaging | MCSE: S+M

Thank you I wonder if it is possible/practical to create new database files (in new location) and move all mailboxes from old database files to new database files ?

No, I would follow the procedure outlined above. I've done it several times, and it works very well.MCTS: Messaging | MCSE: S+M

No, I would follow the procedure outlined above. I've done it several times, and it works very well. MCTS: Messaging | MCSE: S+M But I am curious why it is not feasible?

Sure, it is feasible to create new mailbox databases and move the mailboxes. But I think this requires more administrative effort. On the other hand, you get fresh databases, and as an extra bonus, most of potential logical errors in the mailboxes is fixed by a mailbox move. It might also incur less downtime.MCTS: Messaging | MCSE: S+M