Introduction to Using Exchange Server 2003 Recovery Storage Groups

 

The Recovery Storage Group feature in Microsoft® Exchange Server 2003 allows you to mount a second copy of an Exchange mailbox database on the same server as the original database, or on any other Exchange server in the same Exchange administrative group. This can be done while the original database is running and serving clients. This capability allows you to recover data from an older backup copy of the database without disturbing user access to current data. The recovery storage group can also be useful in various disaster recovery scenarios, most notably the Messaging Dial Tone scenario described later in this document.

Prior to Exchange Server 2003, mounting an extra copy or different version of a production database required the Exchange administrator to build a separate Microsoft Active Directory® directory service forest and recovery server. Not only did this mean that a spare server must be kept available for Exchange database recovery, but building such a server typically requires about two hours of setup time. In Exchange 2003, creating a recovery storage group requires only a few mouse clicks in Exchange System Manager, and the total setup time is approximately two minutes. The process is very similar to creating an ordinary storage group.

After you have created a recovery storage group and added one or more databases to it, you can restore online backup sets to it or copy offline database files into the recovery storage group. You do not have to modify current online backup agents to restore data correctly to the recovery storage group.

Exchange 2003 logically isolates the database copy running in the recovery storage group from the rest of the Exchange organization. Clients cannot log on to this database, and mail cannot be delivered to it. A new version of the Mailbox Merge Wizard (ExMerge) tool must be used to extract mailbox data from this database.

Who Should Read This Guide?

This document is intended for Exchange administrators who have any of the following responsibilities related to an Exchange deployment:

• Creating plans for disaster recovery

• Creating detailed procedures for disaster recovery

• Performing recovery operations

You should have Exchange administrator rights for the administrative group containing the recovery storage group server and local administrator rights on the recovery storage group server.

What Terminology Is Used in This Guide?

To get the most benefit from this book, make sure you are familiar with the following terms:

• Recovery

  To replay transaction logs into a restored database, bringing it into a consistent state. There are two forms of recovery:

  • Soft recovery   A transaction log replay process that occurs when a database is remounted after an unexpected stop, or when transaction logs are replayed into an offline or file copy backup of a database. The replay process uses only log files that are present in the storage group directory.

  • Hard recovery   A transaction log replay process that occurs after restoring a database from an online backup. The replay process begins with any log files that are restored from backup and then continues with other log files present in the storage group directory.

• Replay

  A process in which Exchange examines the transaction logs for a storage group to identify transactions that have been logged, but not incorporated into the databases of that storage group. This process, also known as "playing back" log files, brings the databases up-to-date with the transaction logs.

• Restore

  To put database and log files back into place on a server.