How to Resolve Most Common Exchange Server Database mounting issues?

Updated On - August 31, 2023 by Nasir Khan |

Reading Time: 9 minutes

Exchange Server is a widely used email and messaging platform that allows organizations to efficiently communicate and collaborate with their employees and clients. However, one of the most common issues that Exchange administrators face is database mounting problems. When a database fails to mount, it can result in the loss of crucial data and can lead to significant downtime for the organization. Resolving Exchange Server database mounting issues requires a deep understanding of the underlying causes and the ability to implement effective solutions.

In this blog, we will discuss the most common Exchange Server database mounting issues and provide step-by-step instructions to resolve them. Whether you are a seasoned Exchange administrator or a beginner, this guide will help you troubleshoot and resolve the most common Exchange Server database mounting issues.

Reasons for the Exchange Server Database mounting issues

A dismounted database means that the database is not connecting with the Exchange Server. Below are few of the reasons that arise the Exchange Server Database mounting issues:

How to resolve Exchange Server Database Mounting issue

Error 1: Exchange JET Error 1018

This is the most common mounting error in the Exchange Server that corrupts the Exchange Database .EDB files and displays “JET_errReadVerifyFailure”.

How to Resolve the most-common Exchange Server Database mounting issues

This error occurs due to page-level corruption in the Exchange Database .EDB files that cannot be repaired with inbuilt Exchange Server utility. This error occurs during creation of online backup i.e. cloud backup.


To resolve this issue, try any of the below solution:

  • Online Backup Restoration: Restore log files and database files from the online backup by employing reliable backup media like NTBackup or Windows Server Backup.
  • Restoration using ESEUTIL Command:
    1. Take a backup of the database.
    2. Execute restoration process by Eseutil/p command.
    3. Ensure process correctness by defragmenting the database.

Related Blog: Resolve Exchange 2010 Error “Unable to Mount Database”?

Error 2: Inconsistent or Missing Log Files

The inconsistent or missing log files issue may arise due to human error or issue with backup software. Administrators while freeing up space mistakenly delete log files from Exchange directory and on rebooting Exchange directory, the Exchange Server Database mounting issues appear.


To fix this issue, perform the steps as below:

  1. Copy all the log files to another directory.
  2. Turn ON circular logging to flush the log files.
  3. Mount the database.
  4. Turn OFF circular logging.
  5. Take a full backup of Exchange database.

Error 3: Low or No Disk Space

Exchange, if not provided with adequate storage space or not properly backed up with an application-aware software, consume almost all the space on the drive.


To fix this issue, try any of the three below options:

  1. Take a backup of mailbox database
  2. Manually purge the logs
  3. Increase the storage in case of virtual machine

Error 4: Exchange Database Corruption due to Hardware Failure

Exchange database may get corrupt due to hardware failure such as hard drives, raid controllers, motherboards or other components resulting in Exchange database dismounting issue.


To resolve this issue, rebuild the Exchange Server. To recover Exchange database, use third-party Exchange Recovery software to recover all the data.

Error 5: Exchange JET Error 1216

This error occurs when few important files are deleted, removed, or substituted. This error is reported by the header information assessment in log files and databases.

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This error appears due to abrupt stopping of a running storage group. In case the administrator executes the recovery method, the running file may not include the recovery of deleted files and when the storage group initiates, the header information is examined by the system and the Exchange JET Error 1216 will appear again.


Perform the below steps to resolve the Exchange JET Error 1216:

  1. Execute the command: – ESEUTIL /mh | find /i “consistent”
  2. Execute the command: ESEUTIL /mh | find /I “Shutdown”
  3. Transfer the files to the safe location before undergoing the restoration.
  4. Restore the remaining files by mounting them.
  5. Restore the database from the backup.
  6. Repair the database.

Error 6: Licensing

Exchange Server Standard version has a limitation of only 5 databases. In case you work with more than 5 databases, Exchange will only mount 5 databases and leave the other unmounted.

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To resolve this issue, perform any of the below solution:

  • Upgrade license from Exchange Server Standard version to Exchange Server Enterprise version.
  • Use third-party Exchange recovery software to export from offline database to on online database.

Error 7: Database Mount Error: hr=0x80004005, ec=-501

Unable to mount database (hr=0x80004005, ec=-501)’ error may appear in case of power outage or VM/Physical server has been rebooted.

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Error 8: Exchange Server Database mounting issues: (JET_errFile AccessDenied, cannot access the file, the file is locked or in use)

The above error message appears in case:

  • An application is holding onto the file
  • In case of no anti-virus exclusions in place, anti-virus might either remove log files or lock .edb file to scan it.

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To resolve this issue, perform any of the below solutions:

Error 9: Time Mismatch Error

Error message that appears states –

JET_errDbTimeCorrupted -344 The Dbtime on the current page is greater than the global database dbtime. This error is returned by the directory manager.”

This error appears if the DB and the directory mismatches.


To resolve this issue, perform the steps as below:

  1. Run eseutil /d command
  2. After defragmentation completion, move all the existing mailboxes to a new Exchange Database.

Error 10: Exchange Error 1056749110

The Exchange Error 1056749110 states –
Error was found for RSG, Test because: Error occurred in the step: Moving messages. This mailbox exceeded the maximum number of corrupted items specified for this move mailbox operation, error code: -1056749110.

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Exchange Error 1056749110 message appears when there are some corrupt items present in the mailbox.


Execute the below command to restore the same mailbox (having corrupt items) from Recovery Storage Group to a production mailbox:

Restore-Mailbox -RSGMailbox “RSG, Test” -RSGDatabase MySmpl-Exch \RSG_DB\db11 -id “Recovery, Mailbox” -TargetFolder “Recovered Mails of RSG mailbox” –BadItemLimit 1000

Note: Execute baditemlimitswitch command to skip the recovery of the bad items in the mailbox.

Error 11: Exchange Error 0x8004010F

The Exchange Error 0x8004010F message reads, “Unable to initialize the Microsoft Exchange Information Store Service – Error 0x8004010f”.

This error message appears when the Information Store fails to initialize. This error message disfunctions the smooth functionality of the Exchange Server.

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Exchange Error 0x8004010F appears whenever there is a synchronization issue between the clocks on the Server system and the client’s system.


To resolve the Exchange Error 0x8004010F, perform the below steps:

  1. Restart the Exchange Server.
  2. Ensure that the domain is perfectly configured.
  3. Make sure that the domain is online.
  4. Restart Exchange Active Directory Topology Service.
  5. Launch the command prompt and run Exchange Server as an Administrator.
  6. Execute command – Net time \\ADServerName /Set.
  7. Restart Exchange Active Directory Topology Service.

Error 12: Permission Issue

This issue arises if you modify the SeSecurityPrivilege rights. In occurrence of such an issue. You might receive below events in the Application event log.

Event ID and their Description

  • Event 2102 : Process MAD.EXE (PID=1088). All Domain Controller Servers in use are not responding.
  • Event 9004 : The Metabase Update service failed to start, error ‘80040a01’
  • Event 1005 : An unexpected and unknown error. ID Number – 80040a01 Microsoft Exchange System Attendant occurred.
  • Event 1029 : Failed to replicate the security descriptor to the metabase. Users may not be able to read or write data to the metabase. Error Code – 8000500d
  • Event 9074 : The Directory Service Referral interface failed to service a client request. RFRI is returning the error code: [0x3f0].
  • Event 1121 : Error 0x80004005 connecting to the Microsoft Active Directory
  • Event 125 : A fatal error occurred reading a value from the directory.


To resolve the permission issue that stops .EDB from mounting, perform a domain prep again to put the right back.

Error 13: Anti-Virus

Anti-Virus can delete log files or can lock files, also you may encounter JET_errFileAccessDenied error message when the Exchange database tries to mount.


In case of any anti-virus installed in Exchange, make sure that all the exclusions are set. With correct exclusions in place, it ensures that Exchange runs properly.

Error 14: Exchange Database won’t mount (Cannot see Active Directory)

While trying to mount an Exchange database, you might encounter an error message that states:

Couldn’t mount the database that you specified. Specified database: Mailbox Database; Error code: An Active Manager operation failed. Error The database action failed. Error: Operation failed with message: MapiExceptionNotFound: Unable to mount database. (hr=0x8004010f, ec=-2147221233)

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To resolve this issue, try the below options:

  1. Try and mount the database from the Exchange Management Shell.
  2. Check that Exchange can contact a DC which is a Global Catalog.
  3. Use Set-ADServerSettings command to force the Exchange to use a specific domain controller.

Error 15: SMTP Virtual Server and Connector Configuration

SMTP Virtual Server is an instance of the SMTP service to run the Exchange Server services. It is bound to a particular IP address on Port 25.

The most possible cause of issue with SMTP server is the faulty Server connection along with possible faults in the port value.


The relevant connections must be checked along with the correct port value physically.

Error 16: Dirty Shutdown Issue

Every transaction made in the Exchange Server is kept in the transaction logs. If by fault any of the internal logs get deleted, then the Exchange Server fails to perform and abruptly shuts down.

The dirty shutdown issue appears in case any file from the transaction logs gets deleted.


Keep the backup of all the files. If deletion is required, then check the duplicate of the file to be deleted. Only on finding the duplicate file, delete the target file.

Error 17: Exchange Server reached its Limit (16 GB)

When the Exchange Server 2003 Standard Edition reaches its 16 GB limit, the Exchange Server Database mounting issues appears, and the following technical errors or events are logged:

Event ID and their Description

  • Event 1112 : The Exchange Server mailbox has reached its threshold, has reached the maximum allowed size. Trying to unmount the database.
  • Event 445 : Information Store (3160) The database “D:\Program Files\Exchsrvr\MDBDATA\priv1.edb” has reached its maximum size limit. If the database cannot be restarted, an offline defragmentation may be performed to reduce its size.

This is a common issue in Exchange Server 2003 Standard Edition and occurs when the Exchange Server mailbox limit exceeds 16 GB.


Recovery Storage Group (RSG) feature of the Exchange Server 2003 allows you to easily mount the database from the storage group. Use the Exchange Merge Wizard (Exmerge.exe) to extract mailboxes from the database. Try some other methods to reduce Exchange user mailbox size.

An Automated Tool to Fix Exchange Database mounting errors

It is highly recommended to use a third-party solution – Regain Exchange Recovery tool to avoid any data loss and restore the mailboxes on the Server. The tool restores mailboxes on Live Exchange Server and resumes mailbox connectivity lost due to dismounted Exchange mailbox database.

Free Download100% Secure Buy NowPrice: $89

Regain Exchange Recovery tool is a powerful and reliable software that can help you to resolve various Exchange Server errors, such as database corruption, dirty shutdown, and other issues. Here are the steps to use Regain Exchange Recovery tool to resolve Exchange errors:

  • Download and install the Regain Exchange Recovery tool on your system.
  • After installation, launch the software, and select the corrupt Exchange Server database file (.EDB).
  • Once the scanning process completes, the tool will display a preview of recoverable data. You can select the mailbox items that you want to recover.
  • Now click on the Export option from ribbon bar and choose the target to store the recovered data.
  • Provide Exchange credentials and the software will automatically map the source and target folders.

By following these simple steps, you can easily resolve various Exchange Server errors using Regain Exchange Recovery tool. The tool is easy to use and can recover your Exchange Server database quickly and efficiently.

Software Features:

  • Ensures complete backup of Exchange Server data without any data loss.
  • Allows saving backed up Exchange mailbox in PST, EML, EMLX, MBOX, and MSG file formats.
  • Supports multiple backups from Exchange database.
  • Backup all mailbox folders.
  • Retains original formatting of data.
  • Allows excluding Empty and Deleted Items folders.
  • Allows selecting mailboxes and public folders to take backup.
  • Backup Exchange Server data to Office365 account.
  • Offers incremental backup feature.
  • Allows selective backups of Exchange Server mailbox folders.


This article discusses about the various reasons that might be responsible for Exchange Server Database mounting issues. For each reason, we have explained the manual solution for how to resolve that issue. Also, we suggest to use a third-party solution to restore mailboxes on Exchange Server.

Author: Nasir Khan

I am Nasir Khan from India, working as a Content Developer in Regain Software. Here I am writing about our products and their updates. And writing some free solutions from converting emails or Cloud Migration process. We have tools like Email Converter, Emails backup and Cloud migration.

One thought on “How to Resolve Most Common Exchange Server Database mounting issues?”

  1. Avatar Jennifer Swiger says:

    Thanks to the author for a detailed overview of Exchange Server database mounting issues and their solutions. It is very helpful for someone who is looking for a comprehensive guide to troubleshoot and fix the issue. Thanks for sharing!

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