See also :
Applies to Exchange 2010 and above.
So you have deployed Exchange in your environment, and everything is working fine. Now you want to perform a regular database recovery operation as part of a yearly routine, or may be you want to do actual recovery for a database to restore a mailbox.
The first you think of is the need to create Recovery Database somewhere to perform the recovery, and you start looking for a candidate server with enough storage to host the Recovery Database. When you find one, you will start the restoration and you pay big attention not to write over an actual live database files, and start creating temp folders and so on.
You then have to remember to clean all those files when you are done, hoping that everything will be fine.
My recommendation is to have a separate Exchange server with Mailbox Role on it, and not member of any DAG, with big LUN on it that can be used to restore databases. When you get a recovery request, then you create a recovery database on that separate mailbox server, and you are sure there is a LUN ready for you. Also, you will not be afraid to accidentally delete important files on this server, as it does not host any live databases.