Exchange server is a server application that supports storage for data and other Email objects in its database. Exchange server stores its user mailbox data into EDB format. The user mailbox (e-mails, calendars, tasks, events, and contacts etc.) data is stored in EDB file. Like other data files these files are also prone to corruption. The database can get corrupt due to:Dirty database shutdown, antivirus scanning, log file issues, and others.
The corruption to data may be minor or severe. If the data corruption is minor then, it can be ignored at initial levels but must be cured before it becomes severe and your mailbox data turns unusable.
Exchange Information Store corruption:
- Dirty Exchange Server shutdown is the most common reason that can lead The Information Store to crash while an attempt is being made to access the corrupt database. In this option the primitive step is to restore the database from an updated backup copy and then it can be re synchronized with the transaction logs.
- Information store can also fail to start due to hard disk crash or bad sectors present within it. Hard disk bad sectors turn the stored data unreadable that leads to problems while a database is mounted or a data access attempt is made.
- The Exchange database EDB files are prone to damage due to virus attack or some other malicious application which may lead to file header corruption. Once the EDB file header gets corrupt you cannot access the stored mailbox items.
You will face several troubles while accessing corrupt Exchange Information Store such as:
- Information Store service couldn’t be started
- If it’s already in running state, then it could not be stopped
- Exchange user will be unable to perform Email operations such as sending or receiving e-mails
- The information store just hangs up giving no response and the consume maximum of the CPU resources thus increases it usage and slow down the whole system.
- Clients cannot perform the Email operations such as retrieving and sending mails.
While the Exchange database gets corrupt then the user mailbox data turns out to be unusable or inaccessible. In such situation Exchange recovery is required.
If you are dealing with minor corruption of the database then it’s better to take a backup of the database so that if further damage occurs then you can restore the data from the backup and avoid nay data loss situation. After that run isinteg to fix database issues
In such situation you will try to resolve the problem by restarting the Exchange server but it will not help you.
The next possible steps are to restore the Exchange database from an offline backup. Then run Isinteg utility to perform database integrity check. But you can get the below error:
"Error 4294966746: JET_errDatabaseInconsistent"
You must carefully examine every event of the application event log so that you must be able to identify the errors occurred while the Information Store was being started.
eseutil /mh command can be used to Verify the integrity of both Priv.edb and Pub.edb then, repeat all the transaction log by running soft database recovery.
Cause of the Error:
- The error indicates that the Exchange Information store has got corrupt.
- The corruption can occur in public store or private store or both.
Solution to Fix the Error:
1. The first step you need to do is to analyze the application event log. This will let you know about all the error message and events that were reported by the Exchange server while an attempt to start the he Information Store has been made.
2. Now check the integrity of Exchange databases
By running the eseutil /mh command for Priv.edb and Pub.edb files.
An inconsistent database indicates a ‘Dirty Shutdown' state, it is not the necessary case that database has been corrupted always. If the transaction logs have not been committed then also, you have to face the above situation.
3. Perform soft database recovery to Replay the entire transaction log. Soft database recovery can be performed by running eseutil /r command.
4. Now, Run Run eseutil/ p command to perform hard database recovery. After executing the command, delete all the .chk and .log files.
Check if this resolves the above problems or not. If you are able to work with your Exchange database then, congratulations you have recovered your Exchange data. But if the symptoms still persists then go to the next step.
5. Defragment the database by running eseutil /d command
Run isinteg -pri -fix -test alltests command to fix database issues.
After restarting the information store you need to Run the Directory Service/Information Store (DS/IS) Consistency Adjuster. It is used in disaster recovery scenarios.
Such common scenarios are:
- The folder couldn’t not be restored on the recovery computer due to some reason.
- If the copy of Priv.edb or the Pub.edb files has been created on a system that has different name from that of the original server.
If you can still access and work with the directory service and Exchange Server has been re-installed to a clean folder, then there is no need to run this tool.
Let’s summarize the above used commands in brief:
With the help of above command, your problem will be resolved. But if these commands fail to recover your Exchange data then, you would require some alternative Exchange recovery software.
You can try some Exchange recovery software to regain access to your corrupt EDB database. These tools provide powerful feature that let you repair the corrupt EDB file data and restore the items within it.