Similar to recovery storage groups, recovery databases were designed to recover individual items or mailboxes. Recovery databases differ from recovery storage groups, however, in that they should be used only as recovery targets. Exchange also treats them differently than other databases.
For example, Exchange Server 2010 does not perform a nightly maintenance cycle on recovery databases. You can’t create mailboxes in a recovery database either, and you cannot connect restored mailboxes to a mailbox without copying it to another database first.
Creating a recovery database in Exchange Server 2010
When using recovery databases, you cannot create a recovery database through the Exchange Management Console (EMC). You’ll need to open the Exchange Management Shell (EMS) and enter the following cmdlet:
New-MailboxDatabase –Recovery –Name <database name>-Server <mailbox server name>
The syntax used to create a recovery database is similar to the one used to create an ordinary mailbox database. The only difference is that you must use the –Recovery switch to inform Exchange Server that you’re creating a recovery database.
After creating a recovery database, you can restore a backup to it. You can only use a recovery database with a backup of an Exchange 2010 mailbox database. Exchange 2010 doesn’t support legacy mailbox databases or public folder databases.
Recovery types in Exchange 2010 recovery databases
Restoring your backup to a recovery database is only the beginning of the recovery process. There are four primary types of recoveries you can perform after a restoration:
Dial tone recovery -- With a dial tone recovery, you can provide users with empty mailboxes after a failure, which allows them to send and receive mail immediately. You can then restore the backup of the mailbox database to a recovery database and merge its contents into the new mailbox database.
Alternate server dial tone recovery -- This type of recovery is similar to a dial tone recovery, except the dial tone database is hosted on an alternate server.
Mailbox recovery -- You can recover a mailbox that has been deleted. It is actually more efficient to recover the mailbox from the dumpster than a recovery database; however, a recovery database may be your only option if the mailbox’s retention period has expired.
Specific item recovery -- This process lets you recover individual items from a user’s mailbox.
How to retrieve items from an Exchange 2010 recovery database
To recover items from a recovery database, you generally have to work with the Restore-Mailbox cmdlet. For example, if I wanted to recover a mailbox called Brien from the RDB recovery database, I would use the following command:
Restore-Mailbox –Identity Brien –RecoveryDatabase RDB
To use another example, suppose that a user named Fred left your company and his mailbox was deleted. A new employee, Jane, is hired and needs access to all of Fred’s old messages. Exchange Server 2010 allows you to create a folder called Recovery in Jane’s mailbox and place Fred’s messages into that folder. Jane can move certain messages into one of her folders and delete any unwanted messages. The command used to perform this action is:
Restore-Mailbox –Identity Fred –RecoveryDatabase RDB –RecoveryMailbox Jane –TargetFolder Recovery
ABOUT THE AUTHOR
Brien M. Posey, MCSE, is a seven-time Microsoft MVP for his work with Windows 2000 Server, Exchange Server and IIS. He has served as CIO for a nationwide chain of hospitals and was once in charge of IT security for Fort Knox. For more information visit www.brienposey.com.
This was first published in January 2011