When accessing your Exchange mailbox database, you may encounter a mounting error message, such as “Exchange server database won’t mount”. This error happens due to multiple reasons, for example, malware intrusion, wrong antivirus installation, missing log files, corrupted database or permission issues. You can recover the corrupt database using a recent backup file.
If the backup does not work, use Eseutil, the command-line utility that performs soft recovery and then hard recovery (if required) to resolve this issue. If the error remains unresolved, using an Exchange recovery tool becomes an unavoidable need. We will discuss all these methods in detail right here.
What is the reason behind ‘Exchange database fails to mount’ error?
You may come across the following error when trying to use mailbox database in the Exchange Server Exchange 2019, 2016, 2013, 2010, or 2007:
Unable to Mount Database (hr=0x80004005, ec=1108)”
This Exchange Server error can result because of multiple reasons:
- Corrupt or damaged Exchange database file
- Improper or Dirty Shutdown, leading to uncommitted transaction logs
- The required transaction logs are corrupt or missing
- The drive storing the database has insufficient space
- The installed antivirus may be creating issues in accessing the database files
- The user account does not have the permission to access the database
Steps to resolve the database mounting issues
Here are the steps to fix the Exchange Server database won’t mount and similar errors that create problem in mounting database:
Step 1: Exchange Server services restart
The foremost step to resolve this error is to verify the running status of the necessary Exchange Server services. This includes Microsoft Exchange Information Store, which manages mailboxes and public folder databases. Stopping this service will make the mailbox inaccessible, causing a failed launch of dependent services. Therefore, it is crucial to restart this and related services to restore functionality. Here are the steps:
- On your keyboard, press a combination ‘Windows Key + R’
- In the resulting dialog box, type services. MSc and press Entre
- In the services window, search for the following services:
- Microsoft Exchange Information Store
- Microsoft Exchange Mailbox Replication services
- Right-click the selected service, and choose Start
- In case of stopped or disabled service status, click Restart
Step 2: Database mounting through soft repai
If restarting the crucial services does not mount the database, your next steps should be to perform soft repair by running the following Eseutil command directly from the command prompt.
Eseutil/r
Before running this command, take care of the below points:
- Make sure to have a valid database backup
- Check the state of the Dirty Shutdown state of the database by using Eseutil/mh command
- Ensure to have free disk space, which should be around 1.2 times the database size on the drive
- Explicitly define the Database path, Log file path, and Log file prefix
- Do not run Eseutil command directly on a passive DAG copy. Instead, remove the passive copy and run the command on an active and standalone copy before reseeding.
A successful soft recovery will show the ‘Clean Shutdown as the database state. You can proceed to mount the database on the Exchange Server using EAC. Here are the steps:
-
- Open Exchange Admin Center (EAC) with admin credentials
- Go to Servers > Databases
-
- Select the repaired database
- Remount the database by clicking on More Options > Mount
As an alternate method, Mount-Database PowerShell cmdlet can also help to remount the database. For this, you will need to run the following command in the Exchange Management Shell as a Sysadmin.
Mount-Database -Identity
If despite performing this operation, the database shows dirty shutdown state and the mounting error persists, chances are higher that it has become corrupt. This will necessitate the need for hard repair.
Step 3: Database mounting through hard repair
If the soft repair fails, you can opt for hard repair using Eseutil/p command. Before moving, ensure to follow some major prerequisites for the repair task:
- Restart the server to find out if the problem persists or has been resolved
- Do not forget to create a copy of the database before opting for its repair. You can search the location of your database in the Exchange system Manager > database properties
- As already mentioned, your server should have adequate space to accommodate the repaired file
Here are the steps to perform hard repair:
- Find the status of the database:
Eseutil /mh DB01.EDB
- If it is a Dirty shutdown, follow the complete repair command as given below
Eseutil /P c:\exchsrvr\mdbdata\DB01.EDB
This command line will repair the database file DB01.EDB located on C directory
- Next, run the defragmentation command offline:
Eseutil /d “C:\Exchsrvr\MDBDATA\DB01.EDB
This command removes the empty spaces from the Exchange database, allows server to read data faster, and rebuilds space trees and indexes of the database.
- After this, again check the status by using Eseutil/mh command. If it shows clean state, use Mount-Database cmdlet to mount the database.
Please note that this hard repair will remove the damaged data from the restored database. Therefore, it is good to have a backup of the database. To proceed with data repair without loss of data, using an Exchange recovery tool can be a safer option.
Step 4: Database repair using an Exchange recovery tool
When the ‘Exchange database fails to mount error’ does not resolve by any of the manual methods, using an Exchange recovery application is a comparably better and more effective recovery way. These advanced tools enable admins to fix Exchange Server issues such as Dirty Shutdown error and Jet Exchange error. Usually, these errors remain unresolved due to restrictions of inbuilt utilities, like Eseutil commands, PowerShell and EAC. Here are some of the common features you can expect from these Exchange recovery tools:
- Set you free from the ‘Exchange database fails to mount’ and similar issues
- Help to quickly regain access to damaged EDB files and the included mailboxes
- Convert EDB files to several other formats, including MSG, EML, HTML, PDF or RTF
- Save at the most 4 mailboxes to PST, Live Exchange Server or Office 365 at once
- Enhanced preview of the restored mailboxes and the contained email items
Among the many Exchange recovery tools existing in the market, Stellar Repair for Exchange is a viable option to ensure prompt resolution of the database mounting error. You can order this software from the official website of the concerned company itself.
Conclusion
Your Exchange database file may show mounting error due to several reasons. It could be a permission issue, wrong antivirus installation, corrupted files and so on. In any case, quick resolution of the issue becomes crucial to resume the functionality of your organization at the earnest. You may try the resolution in several steps one after the other.
For instance, to start with, restoring the database from the backup file is an instant method to fix the issue. However, if it does not work, you can proceed with soft repair, which requires the execution of the Eseutil/r command after confirming the Dirty Shutdown status of the database through Eseutil/mh command.
If the repair is a success, you can mount the database by using Mount-Database –Identity command. Else, move to the hard repair process, which involves running Eseutil/p command. Since it will delete the data from the corrupted files, it is better to have a prior backup of the database file before starting the repair.
These methods to fix Exchange database fails to mount error can succeed in resolving the mounting error but have several limitations in terms of time constraint, efficiency, and exhaustive methods. To overcome such hassles, admins prefer to use Exchange recovery tools such as Stellar Repair for Exchange.
