What is the exchange database unknown error?

Businesses all over the world use Exchange servers for email exchange and communication. Normally when an Exchange database is healthy and mounted on the Exchange server, users can access their mailboxes and messages. The database may also be dismounted or the Exchange server might encounter Jet engine errors, in which case users will be unable to access their mailboxes. However, in some cases, the Exchange database displays the status as unknown. When you check its status from the Exchange admin center (EAC) or PowerShell cmdlets, you may see the error message 'Exchange database status unknown.' Even when the database is mounted, the error 'Content index state: Unknown' can occur, affecting Exchange server performance and email flow to and from mailboxes. When the Exchange server is not a part of any DAG environment, there is no automatic database recovery and you must manually resolve the errors in such cases.

The following are some of the reasons for Exchange database unknown error

1. The Exchange database is corrupted or damaged
2. The Exchange server services are not running
3. The database is renamed from the Exchange admin center

1. How to resolve the error Exchange database status unknown?

   You can resolve the error with the following methods:

   • Method 1: Restart the Exchange server and Exchange services

     IT administrators sometimes fail to restart the Exchange server after updating the database name or making changes to it. These changes will not be synchronized with the Exchange server which displays the error. A simple restart of the Exchange server can help you to solve the problem.

     Check if the Exchange services are in the running state

     1. Press Window Key + R and type services.msc
     2. Find the services related to the Exchange server, right click on the item and select 'Restart'

     After you restart, check the database status in the EAC and it should display as Mounted. If it shows Dismounted or remains in the Unknown state, follow the next steps.

   • Method 2: Check the database status from the EAC and remount it

     If the database fails to mount even after an Exchange server restart, remount the database from the EAC or by using PowerShell cmdlets.

     1. In the EAC, go to 'servers' and click 'databases'.
     2. Select the Exchange database whose status shows unknown
     3. Click on 'More Options' and select 'Mount' to remount the database

     To remount the database status with the PowerShell, run the Mount-Database cmdlet on the Exchange Management Shell (EMS) as an administrator.

     Mount-Database -Identity

     Dismount-Database -Identity

     The is the one which shows the status as Unknown

     If the database error still persists even after you mount it, then most likely your database is corrupted and you must repair the corrupted EDB file.

   • Method 3: Repair the Exchange database (EDB) with Eseutil

     Eseutil is a Microsoft built-in command line utility for performing both Soft Recovery and Hard Recovery on the database. Navigate to the directory where your Exchange server is installed and launch eseutil.exe

     1. Check the database consistency with the cmdlet eseutil/mh

        Run the following cmdlet with Eseutil on the Exchange database which shows the status as unknown.

        eseutil/mh

     2. If the status shows Clean Shutdown, you can remount the database. Run the following cmdlet to mount the database to the Exchange server

        Mount-Database -Identity

     3. If the status shows Dirty Shutdown, you must repair the database

        The Dirty Shutdown indicates that the database is severely corrupted. In this case, there are two types of recovery scenarios, Soft Recovery and Hard Recovery. The Soft Recovery replays the transaction log files and recovers the database state. The Hard Recovery on the other hand does a deep scan and tries to repair the database. However, the hard recovery has the limitation that eseutil purges all the data that it fails to recover, which results in data loss.

        For Soft Recovery operation, run the cmdlet: eseutil/r

        The following cmdlet shows the recovery operation with the path

        eseutil /r E01 /l C:\Exchange\EDB /d C:\Exchange\EDB\DB02

        • r stands for recovery
        • l stands for the location of the transaction log files
        • d stands for the database path
        • E01 is the missing log file you need to copy into the log file folder for the soft recovery operation.

        For the Hard Recovery operation: eseutil/p

         See how to repair Exchange database with Eseutil

        Limitation: The database repair method with Eseutil requires thorough knowledge of PowerShell scripts and results in a data loss if the utility is unable to recover the data. In the following section, we describe the best method to recover a corrupted EDB file and perform a direct EDB to Exchange server migration.

   • Method 4: Repair and migrate EDB to Exchange with EdbMails tool

     EdbMails EDB to PST converter is a Microsoft partnered Exchange recovery solution that can completely recover the EDB file without data loss. It is a graphical interface tool that can convert EDB to PST or migrate your mailboxes and email data to Live Exchange. It can repair the EDB from the error 'Exchange Database status unknown' in 2019, 2016, 2013, 2010 and 2007 versions. The following steps describe the recovery and migration with the application.

     1. Download EdbMails Exchange recovery tool and install the application on any computer that is connected to the source and target environment. You can also perform the recovery and migration operation by installing EdbMails on any non-Exchange server computer.
     2. Launch the application and click 'Login' or 'Start Your Free Trial'
     3. Select the recovery technique as EDB to PST. EDB to Office 365. EDB to Exchange.

      See a detailed list of EdbMails system requirements and make sure you have Outlook installed if you want to recover and convert the EDB to PST file. If you want to directly migrate the EDB file to a live Exchange server, you do not require Outlook. Take a complete backup of the EDB file before you proceed with the operation.

     • Step 1: Select the corrupted Exchange database file for recovery

       Select the EDB file that displays the error ‘Database status unknown’. EdbMails thoroughly recovers the file and displays all your mailboxes where you can preview individual mail items. The application can convert mailbox.edb, pub.edb, priv.edb and STM files.

     • Step 2: Select the mailboxes to perform the export or migration operation

       Select the mailboxes and perform the export or migration operation Select the mailboxes, folders and mailbox items and click ‘Migrate to Live Exchange’ to perform a direct Exchange migration. The application supports moving mailboxes to Exchange server 2019, 2016, 2013 and 2010. If you want to export the recovered mailboxes to PST files, click 'Export to Outlook PST'.

       

       You can apply the advanced filter settings to export or migrate the Exchange emails based on Date, Subject, Attachment and so on.

       1. The 'Exclude Standard / Custom folders' option enables you to exclude the folders such as Inbox, Sent, Drafts, Custom folders, Junk, Conversation History from the export operation.
       2. EdbMails comes with other additional settings for export such as splitting a PST file and excluding emails whose size is greater than a specified limit.

       

     • Step 3: Connect to the target Exchange server and map the mailboxes

       Select 'Connect using Global admin User' and select 'Connect to Mailbox(es)'. You can also connect to a specific user mailbox or load a list of user mailboxes by using a CSV file. See the instructions on how to use the different Exchange server connection methods supported by EdbMails.

        With EdbMails, you can migrate mailboxes, public folders, and archive mailboxes from the source Exchange to the target server.

       

       

       The mapping activity in EdbMails can automatically match and map the mailboxes and folders with the Exchange server and saves time when you’re migrating a large number of mailboxes.

     • Step 4: Start the migration from the EDB file to Exchange server

       After you complete the mapping, start and monitor the migration. Finally, verify the count of migrated emails, folders and mailbox items with EdbMails text-based log report. With this method, you can safely migrate all your mailboxes from the corrupted database file to another Exchange server.

       Tip: EdbMails also supports mailbox migration from EDB to Office 365.

       

        If you require further assistance, contact EdbMails 24x7 support. Try the free trial version today to recover and restore Exchange server data. See steps to recover and convert the EDB file to PST