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EDB files corruption is one of the worst nightmares for Exchange Server users. At times, when you try retrieving your data from MS Exchange Server, the process fails, and you receive the error message mentioned below:
Access denied to database Mailbox Store (SERVER2K3).
WARNING: \\SERVER2K3\Microsoft Information Store\First Storage Group\Mailbox Store (SERVER2K3) is a corrupt file.
This file cannot verify.
Database or database element is corrupt
This error message means that you might lose your important data. However, to restore accessibility and resolve corruption, you might need to check the Exchange logs for error messages and see if Exchange services are running correctly.
What causes corruption in EDB files?
Just as you protect other critical data, it’s essential to safeguard data stored in the mailboxes of the Exchange database. There can be innumerable reasons causing this corruption in the Exchange database files, and some of those are hereby mentioned:
- Either you do not have the required permissions to access the database.
- Some of the precious Exchange Server files are missing.
- EDB database files are corrupt, and data has become inaccessible.
- Sudden power failure causing the EDB files to be inaccessible.
- Unpredicted shutdown of Exchange has led to the Dirty Shutdown.
To fix this problem, you must have appropriate permission from the administrator and try again. Either you can repair your Exchange Server by using the Eseutil.exe tool, or Exchange Server can be repaired by using a third-party Exchange Server repair tool. Corruption of the Exchange Server database is a very crucial situation, and it needs to be repaired as early as it can be.
What are different Exchange database corruptions?
There are two types of database corruption that usually occurs in an Exchange Server:
Physical corruption: Exchange server corruption that is a result of hardware breakdown or inefficiency, is physical corruption. This is the lowest level of corruption in the Exchange Server. Some errors that you may encounter during physical corruption include:
- 510 JET_errLogWriteFail
- 528 (JET_errMissingLogFile)
- 529 (JET_errLogDiskFull)
- 548 (JET_errLogSequenceEndDatabasesConsistent)
- 1018 (JET_errReadVerifyFailure)
In case of physical corruption, you can try restoring database using backup. However, if, due to any circumstances, backup is unavailable or outdated, you can try repairing the Exchange database using utilities like Eseutil or recovering mailbox data using Outlook PST generated using a professional Exchange recovery tool.
Logical corruption: Logical corruption or soft corruption occurs within different levels of the software. It usually occurs due to jet engine database failure or invalid indexing. Logical corruption is of two types: Database logical corruption and Store logical corruption.
- Database: It happens when the database engine attempts to write a database page. Even though the operating system indicates a successful message, the data is either not written or gets written to the wrong location.
- Store: Third-party applications can unexpectedly add, delete, or manipulate data, which may be seen as corruption by the user. In Exchange Online, the In-Place Hold feature helps prevent permanent deletion of content by users or applications, thus protecting against logical corruption.
Implement in-built utility Eseutil for Exchange Server repair
Eseutil.exe is an inbuilt Exchange Server utility that enables users to repair .edb files. However, if you want to fix this corruption error, you will have to perform EDB recovery. Eseutil repair process involves rebuilding the Exchange database and eliminating invalid data during the process. Before running the Eseutil application, users must ensure the following requirements.
- Exchange Database backup is taken.
- Exchange Database is dismounted (Run Dismount-Database –Identity
in PowerShell). - Minimum 20% of total disk space is there.
These are mandatory requirements, and after fulfilling these, you can start the repair process through Eseutil commands. You can find and open the Eseutil application by visiting this path: C:\Program Files\Microsoft\Exchange Server\V15\Bin
Step 1: Check your database state
Run the following Eseutil command to find out the current state of your Exchange database:
ESEUTIL /MH <database name>
Step 2: Perform soft recovery
If the status is Exchange Dirty Shutdown and the output shows missing logs, you can perform soft recovery by running this cmdlet.
ESEUTIL /r <log prefix> /l <log files folder path> /d <database folder path>
Step 3: Go for hard recovery
Check the status again and if soft recovery does not work, try performing the hard recovery. Use this cmdlet.
ESEUTL /P <database path location>
Users can recheck the database state and can find if the Exchange Database is in a healthy state or not. However, one cannot guarantee that the database gets repaired, or no data loss happened during the process. The best solution to go with would be a professional EDB recovery solution to access the Exchange data once again without any data loss.
Repair EDB file corruption using a professional EDB repair tool
Kernel for Exchange Server recovers mailboxes from corrupt, damaged and inaccessible EDB files of MS Exchange Server. Moreover, it recovers all emails, notes, contacts, journal, calendar entries, and other items from the inaccessible mailboxes. Exchange Server recovery software supports exchange database recovery from EDB files created using Exchange Server 5.0, 5.5, 2000, 2003, 2007, 2010, 2013, 2016, and 2019. It is user-friendly and easy to use software that ensures high accuracy in EDB recovery.
Conclusion
Minor corruption and accessibility issues within the EDB files can be resolved using Microsoft utilities like Eseutil and Isinteg. However, this approach is not reliable in case of severe corruption and can lead to data loss. You can use Kernel for Exchange Server to recover database from corruption and retrieve data from the Exchange database files.