To resolve ‘Exchange Database Fails to Mount’ error, you need to first ensure that all the required Exchange Services are up and running and the disk storing the EDB and log files has sufficient free storage space. Also, check if the backup and antivirus software are application-aware.
If the database still doesn’t mount, try to restore it from a healthy, updated backup. In case the backup is not updated or available, then perform soft recovery using Eseutil /r. However, to recover corrupt Exchange database without any data loss, you can use an Exchange repair tool. In this article, we will discuss these solutions in detail and help you to resolve the database fails to mount error.
What is ‘Exchange Database Fails to Mount’ Error?
When users can’t send/receive emails, schedule meetings, or perform any task, you should check if the database is mounted or not. This can be done via the Exchange Management Shell (EMS) or the Exchange Admin Center (EAC). If the database is dismounted, you should mount it immediately. But sometimes when you try to mount the database, you get an error like the one below:
'Unable to mount database (hr=0x80004005, ec=-528).
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Microsoft Exchange Error
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Failed to mount database 'EXDB01'.
EXDB01
Failed
Error:
Couldn't mount the database that you specified. Specified database: EXDB01; Error code: An Active Manager operation failed. Error The database action failed. Error: Operation failed with message: MapiExceptionJetErrorMissingLogFile: Unable to mount database. (hr=0x80004005, ec=-528)
. [Database: EXDB01, Server: mail.mycompany.com].
An Active Manager operation failed. Error The database action failed. Error: Operation failed with message: MapiExceptionJetErrorMissingLogFile: Unable to mount database. (hr=0x80004005, ec=-528)
. [Database: EXDB01, Server: mail.mycompany.com]
An Active Manager operation failed. Error Operation failed with message: MapiExceptionJetErrorMissingLogFile: Unable to mount database. (hr=0x80004005, ec=-528)
. [Server: mail.mycompany.com]
MapiExceptionJetErrorMissingLogFile: Unable to mount database. (hr=0x80004005, ec=-528)
What are the Reasons for Exchange Database Fails to Mount Error?
An Exchange database may fail to mount on the server due to different reasons, such as:
- Some Exchange services are stopped
- Log files are missing or corrupted
- Insufficient storage space on the disk/drive where the database is stored
- Conflicting antivirus or any other third-party application
- Database file is corrupted
- Backup software is not application-aware
How to Resolve ‘Exchange Database Fails to Mount’ Error?
Here are some methods that can help you resolve the Exchange database fails to mount error.
Method 1: Check and Start the Exchange Services
It might happen that some Exchange Server services are not running that are causing the issue while mounting the database. So, you can check that if any services are stopped. If there are any, then start them to resolve the issue. Follow the steps mentioned below:
- Open the Server Manager. Click on Tools and select Services from the list.
- On the Services screen, check that all the services of Exchange Server are running. Make sure that any service, which has the Startup Type set to Automatic, is started.
- If the status of any service(s) is Stopped, right-click on it, and select Start.
 is Stopped, right-click on it, and select Start..png)
Alternatively, you can use the following PowerShell cmdlet to restart all the Exchange services:
Once all the services are started, try to mount the database. If the issue persists, follow the next method.
Method 2: Check the Disk Space
If there is lack of space on the disk where the database and transaction logs are stored, then you may face issues when mounting the database. To check disk space, use the following PowerShell command:
The above command will list all the drives supported by Windows PowerShell File System provider, along with details related to free and used storage space. You can check the ‘Free’ space of the drive, where the database is stored. If the space is low, then try to free up the space by deleting unwanted data or add a disk with more storage capacity.
Method 3: Check if Backup and Antivirus Software are Application-aware
If the backup software is not compatible with the Exchange Server installed, it will result in incomplete or unhealthy backups. If the backup software is not taking the backup properly, then the log files will not be committed and get piled up, filling up the disk space. This will cause issues while mounting the database on the server. You can verify that the backup software is application-aware and compatible with your Exchange Server. You can use Windows Server Backup, recommended by Microsoft.
If your antivirus software is not application-aware, then it can cause problems in Exchange Server. So, make sure that your antivirus software is compatible with your Exchange Server. You can check this with the antivirus provider or vendor.
Method 4: Restore the Database from Backup
If the above methods fail to resolve the issue, then it means that the database or log files are corrupted. In such a case, you can restore the database from the latest healthy backup. However, restoring the database from backup means that any changes, from when the database is updated till the time when the issue has occurred, will be lost. For example, if the backup was last updated 24 hours ago, then all the emails, tasks, or any other changes, of an entire day will be lost.
Method 5: Repair the Exchange Database
If you don’t have an updated backup, then you can repair the corrupted database using the Eseutil. Here’s how you can use it to repair the database.
First, you need to use the Eseutil /mh command to check the state of database (see the below example):
If the database is in Dirty Shutdown state, you can perform Soft Recovery on the database by replaying the Logs Required to bring mailbox database to a Clean Shutdown state. To perform Soft Recovery, run the following command:
Once the process is completed, check the database status again using the Eseutil /mh command. If it shows the database state as Clean Shutdown, you can mount the database. However, if it still shows the database state as
Dirty Shutdown, then you can perform Hard Recovery by using the below command:
It is to be noted that the hard recovery process can result in data loss as it purges any data that is deemed as corrupted. Additionally, Microsoft will not provide any support after hard recovery as the database will be hard coded. Furthermore, there is no guarantee that the process will work and recover the database.
How to Repair Corrupted Exchange Database without Data Loss?
To avoid data loss and to quickly repair the corrupted Exchange Server database, you can use Stellar Repair for Exchange - a specialized Exchange recovery tool recommended by MVPs. It can help you quickly repair damaged or corrupted Exchange database, even without a running Exchange Server. There’s no risk of data loss as the tool extracts all the mailboxes and other items from the corrupted database and saves them to PST files with complete integrity.
Stellar Repair for Exchange also allows to export the recovered mailboxes from the damaged database (that fails to mount) directly to a new database on live Exchange Server or Office 365 (Microsoft 365) tenant. It auto-maps the source and destination mailboxes and uses parallel processing for faster exports to the destination server. This not only helps you save significant time and effort but also reduces downtime.
Case Study
Eseutil Failed? Worktrainers Ltd. Recovery from Critical Email Outages! - Explore the Full JourneySee how Worktrainers Ltd used Stellar Repair for Exchange
Conclusion
When the Exchange database gets dismounted, it can prevent users from sending or receiving new emails. In such cases, you should immediately mount the database. However, if the database fails to mount, it usually indicates an issue with the Exchange services, anti-virus software, backup software, or disk storage. To fix these issues, use the methods mentioned in this article.
In case Exchange database still doesn’t mount, it indicates an issue with the database. You can restore the database from backup. If backup is not updated, you recover database by performing soft recovery or hard recovery. However, hard recovery can lead to data loss. To avoid loss of data, you can use Stellar Repair for Exchange. This Exchange recovery software can repair even severely corrupted databases without data loss and help resolve ‘Exchange Database Fails to Mount’ error. After repairing the database, you can save mailboxes to PST format or export them directly to live Exchange Server or Office 365 (Microsoft 365) tenant.
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