Hi,
Following on from my post here http://www.adamfowlerit.com/2013/01/02/recovery-storage-groups-in-exchange-2007/, once you’re finished with your Recovery Storage Group, you should clean it up. A rather simple process, you start with this Exchange Powershell command:
Remove-MailboxDatabase -identity <Server_Name>\<RSG_Name>\<Database_Name>
This will do the obvious thing of removing the mailbox database. If you can’t remember what you called your Recovery Storage Group, just use the command ‘Get-MailboxDatabase’ and you’ll see all your databases, and if you’ve named the RSG sensibly, you’ll be fine. One thing I ran into was trying this command from a Windows Server 2008 R2 box, while Exchange 2007 was running on Windows Server 2003. It brought up an error saying that I couldn’t remotely do commands from 2008 to 2003, but when I got onto the 2003 box, the database was gone! If you didn’t have this problem, you should get a message stating that you need to manually remove the database file.
The second step is to remove the Storage Group with the following command
Remove-Storagegroup -identity "<Server_Name>\<RSG_Name>"
Again, run ‘get-storagegroup’ to remind yourself of the name. After this, you’ll get a message telling you to remove the log file:
WARNING: The specified storage group has been removed. You must remove the log file located in h:\path\logs from your computer manually if it exists. Specified storage group: exchange\rsg.
Pretty straight forward. If you don’t clean up your RSG, you may have issues with backup software detecting the extra database.
Source: http://technet.microsoft.com/en-us/library/bb125197(v=exchg.80).aspx