When an Exchange mail stores in a storage group will not mount because of corruption or due to disk failure it is necessary to restore the storage group and replay transaction logs if they are available.

For recovery of individual mailboxes or messages the Exchange Recovery Storage Group is the preferred method of restoration.

Assuming:
C: = System Drive
D: = Exchange Transaction Logs
E: = Exchange Databases

1) Allow Restore from Exchange System Manager:
- Expand Administrative Groups | First Administrative Group | Servers | <server> | First Storage Group
- Right click on Mailbox Store (<server>) and select Properties from the context menu
- Select the Database tab
- Check the This database can be overwritten by a restore checkbox and click OK
- Right click on Mailbox Store (<server>) and select Dismount Store from the context menu
- Click Yes to dismount the store
- Right click on Public Folder Store (<server>) and select Properties from the context menu
- Select the Database tab
- Check the This database can be overwritten by a restore checkbox and click OK
- Right click on Public Folder Store (<server>) and select Dismount Store from the context menu
- Click Yes to dismount the store


2) Restore Data (transaction logs available to replay)
- Create the folder D:\Program Files\Exchsrvr\MDBDATA\Recovery
- Copy all recovered transaction logs to D:\Program Files\Exchsrvr\MDBDATA and overwrite all files
- From Backup Exec select Restore | All Resources | <server> | Microsoft Information Store | First Storage Group
- Ensure the Settings | Microsoft Exchange | Temporary Location for Log and Patch files is set to D:\Program Files\Exchsrvr\MDBDATA\Recovery
- Ensure the Settings | Microsoft Exchange | No Loss Restore is checked
- Ensure the Settings | Microsoft Exchange | Commit After Restore is checked
- Ensure the Settings | Microsoft Exchange | Mount Databases After Restore is unchecked

OR

2) Restore Data (no transaction logs available)
- From Backup Exec select Restore | All Resources | <server> | Microsoft Information Store | First Storage Group
- Ensure the Settings | Microsoft Exchange | Temporary Location for Log and Patch files is set to D:\Program Files\Exchsrvr\MDBDATA
- Ensure the Settings | Microsoft Exchange | No Loss Restore is unchecked

3) Mount Stores from Exchange System Manager:
- Expand Administrative Groups | First Administrative Group | Servers | <server> | First Storage Group
- Right click on Mailbox Store (<server>) and select Mount Store from the context menu
- Right click on Public Folder Store (<server>) and select Mount Store from the context menu
- Reboot the server once stores are successfully mounted.

Backup Exec 11d Best Practices Guide: Agent for Microsoft Exchange Server
http://support.veritas.com/docs/285753

"Be aware of the effect of the "No loss restore" setting. Take note that any transactions which existed in transaction log files left in place following a "No loss restore" operation will play back when starting or mounting the Information Store database. Thus, if there are deletions that occurred after the backup was performed those deletions will play through and may potentially remove the very data that the restore process was intended to recover. In this case, either the Exchange data generated after the backup will need to be discarded by the process of a "Loss" restore operation OR a second recovery server will be needed to perform the restore, (unless the Recovery Storage Group feature of Exchange 2003 is used to perform the data recovery operation)."

"Note that the "Restore in Progress" registry key has been replaced by the Restore.env file. This file contains roughly the same information as the registry value. It is placed in the temporary location during the restore process. This file can be used to troubleshoot issues that may be encountered when trying to mount a store after a restore operation. To read the contents of this file use Eseutil with the /cm switch. Please refer to Microsoft documentation for additional information regarding the Restore.env file."

"If the "Commit after restore completes" option was not chosen during the restore job configuration the database will fail to mount. In this case simply run the Eseutil /cc command to perform a manual hard recovery. Please see Microsoft documentation for additional details regarding the use of the Eseutil command."

Transaction Log File Replay: Soft Recovery and Hard Recovery in Exchange Server 2003
http://technet.microsoft.com/en-us/library/aa997761.aspx

"You may have extra log files to replay that are not from an online backup set. In this case, place those logs in the normal transaction logs folder for the storage group and not in the temporary folder. After hard recovery finishes replaying the logs restored from the backup set, the process checks the normal transaction log folder to see if the next log in sequence is available."