Dial tone portability is a feature of Microsoft Exchange Server 2010 that provides a solution for failures that affect a mailbox database, a server, or an entire site. Dial tone portability enables users to have a temporary mailbox for sending and receiving e- mail while their original mailbox is being restored or repaired. After the users original mailbox data has been restored, an administrator can merge a users recovered mailbox and the users dial tone mailbox into a single, up-to-date mailbox.
The process for using dial tone portability is called a dial tone recovery. Dial tone database :-allows users to send and receive e-mail messages while the failed database is recovered. There are three options for performing a dial tone recovery:- Dial tone recovery on the server with the failed database Dial tone recovery using an alternate server for the dial tone database Dial tone recovery using and staying on an alternate server for the dial tone database
Create an empty dial tone database to replace the failed database Restore the old database Swap the dial tone database with the restored database Merge the databases
You must have fewer than the maximum number of databases deployed to create a dial tone database. Use the Shell to perform a dial tone recovery on a single server Make sure that any existing files for the database being recovered are preserved in case theyre needed later for further recovery operations. Use the New-MailboxDatabase cmdlet to create a dial tone database, as shown in this example. New-MailboxDatabase -Name DTDB1 - EdbFilePath D:DialToneDTDB1.EDB
Use the Set-Mailbox cmdlet to rehome the user mailboxes hosted on the database being recovered, as shown in this example. Get-Mailbox -Database DB1 | Set-Mailbox - Database DTDB1 Use the Mount-Database cmdlet to mount the database so client computers can access the database and send and receive messages, as shown in this example. Mount-Database -Identity DTDB1 Create a Recovery Database. Mount the RDB, and then use the Dismount- Database cmdlet to dismount it, as shown in this example. Mount-Database -Identity RDB1 Dismount- Database -Identity RDB1
After the RDB is dismounted, move the current database and log files within the RDB folder to a safe location. This is done in preparation for swapping the recovered database with the dial tone database. Dismount the dial tone database:-Dismount- Database -Identity DTDB1 Move the database and log files from the dial tone database folder into the RDB folder. Move the database and log files from the safe location containing the recovered database into the dial tone database folder, and then mount the database, as shown in this example. Mount-Database -Identity DTDB1
Mount the RDB, as shown in this example. Mount-Database -Identity RDB1 Use the Get-Mailbox and Restore-Mailbox cmdlets to export the data from the RDB and import it into the recovered database:-Get- Mailbox -Database DTDB1 | Restore-Mailbox - Recovery Database RDB1 After the restore operation is complete, you can dismount and remove the RDB, as shown in this example:-Dismount-Database -Identity RDB1 Remove-Mailbox Database -Identity RDB1
PROS The amount of data that must be merged is minimized. The final database size will be less than if you merged the original data. The original mailbox rules, forms, and other ancillary data will be preserved in the state they were in before the disaster. By using the recovery storage group, you can avoid building an extra server and, if you keep all databases on the same drive, eliminate the time needed to copy large files between disks and servers.
CONS The administrator must have cleared all the Mailbox box prerequisites cleared in order to proceed.
During the first two steps of Messaging Dial Tone recovery, the dial tone database provides service for users while you recover the damaged database
After you swap the two databases, users gain access to previous data
Use Mailbox Merge to bring the recovered mailboxes up-to-date with content that was created during the restore and recovery process