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Tuesday, August 14, 2012

Hard Recovery on Exchange 2007


STEPS FOR PERFORMING HARD RECOVERY ON EXCHANGE 2007


ESEUTIL tool should be used to perform the soft and hard recovery on Exchange. Hard recovery of exchange database is done only when the database is in dirty shutdown state (after soft recovery) /database is corrupted / logs are missing.
ESEUTIL / p is the command for performing hard recovery.
Below are the detailed steps for performing hard recovery on damaged /corrupted database:
·         Command for hard recovery:
Eseutil / P “Database name”
Eg: C:\Exchsrvr\Bin>eseutil /p “D:\Exchange\Mailbox Store.edb”
·         You will be prompted with a warning dialog box, Click OK.


Note: Recovery process may take time depending upon the level of database corruption, available hardware resources. The repair runs at approximately 4 to 6 gigabytes (GB) per hour. 

·         Once the recovery is completed, offline defragmentation should be done on the repaired database. For running defragmentation, the hard drive should be having 110 % of the database that you want to defrag.
·         To defrag, the following is the command:

Eseutil /d “database name”

Eg: C:\Exchsrvr\Bin>eseutil /d “D:\Exchange\Mailbox Store.edb”

·         You will be prompted to confirm the action, please confirm the same.

·         Once the Defragmentation is completed, then integrity check should be done on the defragmented database. Before proceeding with integrity check, Mount the store & Dismount the store immediately after the completion of offline defragmentation.
·         To run integrity check, Isinteg command should be used.
Note:
1.      Isinteg should be run only on offline datastore.
2.      Isinteg runs at approximately 3 to 6 GB per hour. (These rates are average; performance may vary depending on how many passes the repair has to make on your database and the speed of the hardware.

·         To run integrity check, following is the command:
isinteg -s (SERVER) -fix -test alltests
eg: C:\Exchsrvr\Bin> isinteg -s (mailserver) -fix -test alltests
You are prompted to select the database to be checked just like below:
-----------------------------------------------------------
Index                Status               Database-Name
Storage Group Name:  First Storage Group
                1                    Offline              Mailbox Store (servername)
                2                    Offline              Public Folder Store (servername)
--------------------------------------------------------------
·         Enter a number to select a database.
·         Once the selection is done, you will be prompted for Confirmation, type Y for Yes and N for NO.
·         You receive a summary report that indicates the number of tests that were run, the number of warnings, and the number of errors found, the number of fixes attempted, and the time it took for the program to run. If there are any warnings, errors, or fixes, run the command again until the count is Zero.
·         Once it is completed successfully, then mount the database.

Best practices:
We recommend that you follow these best practices (as per Microsoft) when repairing a database:
  • Do not use the Eseutil repair option when you can restore from backups without any data loss.
  • Hard recovery should be done if the soft recovery is failed or the database is still in dirty shutdown state using ESEUTIL.EXE tool.
  • Eseutil tool should be used only on damaged /repaired database.
  • Do not allow a repaired database to remain in production for an extended period of time.The best way is to create a new database and move the mailboxes from the repaired database.