Recovering Messaging Databases

Methods for recovering a database:

- Recover using Recovery Storage Group (RSG)
- Recover using Database Portability
- Recover using Dial-Tone Recovery

Recover data using RSG:

1. Use Exchange Database Recovery Management tool for creatingthe RSG.
2. Restore data using back to the RSG (Note: You don’t need to select an RSG to restore to.. If one exists, it is automatically used.)

Recover using Database Portability:
You can use the database portability feature in Exchange Server 2007 to recover a mailbox database when there is a server failure or a hard disk failure.

You can use this option when a Mailbox server fails, but the storage group and database files are available on hard disk or on a backup tape.

You can also implement database portability when the hard disk storing the database fails on one server, and the hard disk cannot be replaced. You can restore the database from the backup data on another Mailbox server.

By using database portability in Exchange Server 2007, you can move a mailbox database from one Mailbox server and mount it on another server. To mount the database on the new server, you do not need to modify the database or configure the server. However, you can mount the database only on a server in the same Exchange Server organization.

To recover a messaging database by using database portability:

1. First create a new database on an alternate server. The new database must have the same name as the database you are recovering. You can either create a new storage group or create the destination database in an existing storage group on the server. Then, configure the database so that you can overwrite it with the backup data.

2. You can now restore the backup copy of the database from the failed server and mount the database on the new server.

3. Finally, you need to modify the user accounts to refer to the new database by using an Exchange Management Shell command.
This command obtains a list of all mailboxes in the restored database and passes it to the Move-Mailbox cmdlet.

Get-MailboxStatistics -database Move-Mailbox -configurationOnly -target

4. When users try to access their mailboxes by using Microsoft Office Outlook 2007, they will be automatically redirected to the new server. However, you need to manually configure clients such as Microsoft Office Outlook 2003 and earlier versions to refer to the new Mailbox server. Outlook Web Access users are also automatically redirected to the new server.

Recover using Dial-Tone:
You can use dial-tone recovery to provide users with immediate access to their mailboxes and e-mail services even before you restore data to their mailboxes. To do this, create an empty mailbox database to replace the missing or corrupted mailbox database. By using dial-tone recovery, you can ensure that users experience minimum disruption of services after the failure of a database or a server.
Benefits of Using Dial-Tone Recovery
By implementing dial-tone recovery, you can ensure that users in your organization can access their e-mail messages and begin working much faster compared to a standard restore. When you perform a standard restore, users cannot access e-mail services until you restore the database completely. A standard restore can take several hours if the database is very large, and external users may start receiving non-delivery reports (NDRs).
Using Alternate Servers
If there is a server failure instead of a database failure, you can perform dial-tone recovery on an alternate server by using the database portability features of Exchange Server 2007. You also need to modify the user accounts to refer to the new database location.
Recovering Historical Data
After dial-tone recovery is complete, you can restore the data from backup to an RSG and then merge the mailbox contents in the recovered database with the contents in the dial-tone database. All the user mailboxes will now have all of their historical information as well as the received and sent messages since the implementation of dial-tone recovery

Procedure:

1. On another server create a new Storage Group and Create new Database.Note: Use the SAME NAME as the database you'll recover.
2. Open Exchange Mgmt Shell and modify the user accounts to refer to the new database by using an Exchange Management Shell command.
3. This command obtains a list of all mailboxes in the restored database and passes it to the Move-Mailbox cmdlet.Get-MailboxStatistics -database
   Move-Mailbox -configurationOnly -target
4. This will give the users access to their mailboxes, while you prepare to merge backup data from and RSG to the new mailbox database.
5. Use the Exchange Database Recovery Management tool to create a RSG and restore data to the RSG (Refer to Recover using RSG prior section).
6. After db is restored from backup, use Exchange Database Recovery Management tool to merge data from RSG to the new database.
7. Manage Recovery Storage Group > Merge copy mailbox contents > Gather Merge Information
8. At the Select Merge Options > Perform pre-merge tasks
9. Select mailboxes to copy or merge and Perform Merge Actions