Sunday, September 25, 2016

Restoring Exchange Server Database from a Storage Failure (Database is not Mounting)

We all know ‘unable to mount Exchange database’ is the most frequent and common issue faced by Exchange administrators, and database restoration is the last option to get rid of it. However, below are the possible options to get the problem resolved when database storage fails:

    A good and updated Exchange backup is available.

    Exchange database is down.

     Mounting a new or blank or empty database with the messaging kept active until the database is repaired.

    Performing a soft-recovery and fixing the database.

    Opting for a professional Microsoft Exchange Server recovery software.

Let’s now discuss each option to restore the Exchange server database in a step-by- step process:

1. A Good and Updated Exchange Backup is Available 

If you find yourself in the midst of such a situation, the first thing you need to check is whether there is an updated backup on the server. Go for the best Exchange Server backup software to restore the Exchange database from the backup with minimal downtime, but ensure that the live data is retained on the existing storage drive. Once you’ve restored the database from the backup, create a recovery database and repair the failed database and combine it with your process.

But before restoring the database using Exchange backup software, create a copy of the database or just rename it. Using the database without even copying or renaming can override the database file on existing storage drives.

2. What if No Backup is Available and Exchange Database is Down 

If a backup is not available, you then need to verify the health of the database. Because you don’t have any backup copy of the database, and the size is very large (approximately 8-10 GB), it will take several hours to run a successful repair. So firstly, make a copy of the database (if the backup is available) so that if the repair job is interrupted in the middle of the process, you can restart the job with the saved backup copy.

Let’s now examine the health of database:

Open PowerShell and locate the default location of Eseutil.exe. If you couldn’t find the utility, open the following folder location by navigating to the path:

C:\Program Files\Microsoft\Exchange Server\V15\Bin

Next, run the below command to check the health of database:

.\eseutil.exe /mh "D:\log files\Mailbox Database\DB1.edb"

(I) If database is healthy and showing a Clean Shutdown state:

The database still can’t be mounted back to the server because it isn’t able to read and understand current log files sequence. So you need to delete all those log files and then mount the database. Exchange server will generate new log files for the database and mount the database successfully.

3. Mounting a new or blank or empty database with the messaging kept active until the database is repaired.

Follow the steps below:

         i.            Stop Microsoft Search Service and Search Host Controller Service:

       ii.            Now rename the database folder and create the same folder. The server will force you to create an empty database while mounting the store. Soon, when you mount the blank database, Outlook will prompt you to restart the program. 

     iii.            If Outlook is in cached mode, it prompts you with two options; select ‘Use Temporary Mailbox’ to send and receive emails using temporary mailbox or ‘Use Old Data’ if you have a PST file.

Take another case where the database is showing a dirty shutdown state. First, check whether the required log files are available or not. If log files are available, do search for .chk file in the same location. However, in case the log files can’t be located, then try Soft Recovery

4. Performs Soft Recovery (eseutil.exe /r) and Repair the Database

As the log files are missing, you’ll need to get the database in good health.

.\eseutil.exe /r e01 /l "D:\log files\DB1" /d "D:\Program Files\Microsoft\Exchange Server\V15\Mailbox\Mailbox Database\DB1.edb" /a

/D switch stand for database location
/l is used for log file location
/a – database will come in good shape but the possibility of data loss is also there.

By executing the above command, the database will show you a clean shutdown state. Now you can mount the database to the server. But in case it fails, move the log files and try to mount it as the databases are in clean shutdown state. In case Soft Recovery is not of any help, you may then need to opt for Exchange database repair or recovery software.

5. Go for Exchange Server recovery software

Though there are several solutions to fix the issue, yet none promises zero data loss during the database repair process; especially, when you have to repair and mount a large database. Then the chances of database failure as well as data loss increases. 

In such a case, you should always go for an Exchange database repair software that can help you not only repair the database, but also recover and export the database to the live server. 

Stellar Phoenix Mailbox Exchange Recovery software is a conglomerate of all the above features. Whether the database is corrupted, offline, down, or of large size, Stellar Exchange database recovery software lets you repair the database with guaranteed zero data loss and the choice to export the recovered mailboxes to a working live server. Once the process is completed, you can check the generated log report to carefully analyze the database recovery process. 

To view the features and functionalities of the software, you can download the trial version by clicking the url:

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