How to Fix the Error “Database Availability Group Must Have Quorum”?

Summary: In this write-up, we will guide users and provide solution to solve the error database availability group must have quorum.

The DAG (Database Availability Group) is the group of 16 Microsoft Exchange mailbox server which provides automatic database level recovery from the database, network failure or server. It is best for high availability & failover for your Exchange Server and its services.

Some Exchange users / administrator encounter with some issues or error which affect the performance, data integrity, quality, etc… of Microsoft Exchange Server. Here, they also came across the error when users or admin try to mount the mailbox database and receive the following error:

“Failed to mount database “EDB00”. Error: An Active Manager operation failed. Error: An Active Manager operation encountered an error. To perform this operation, the server must be a member of a database availability group, and the database availability group must have quorum. Error: Unable to read from the cluster database. This may occur if the server has recently been removed from the database availability group. [Server: EXCH10.systoolsgroup.com]”

+ CategoryInfo: InvalidOperation: (EDB00:ADObjectId) [Mount-Database], InvalidOperationException

+ FullyQualifiedErrorId: [Server=EDB00,RequestId=c31b861c-43e6-4a79-857f-51824b915ee3,TimeStamp=1/2/20213:52:31AM][FailureCategory=Cmdlet-InvalidOperationException] 7E29F70A,Microsoft.Exchange.Management.SystemConfig
urationTasks.MountDatabase

+ PSComputerName: EXCH10.systoolsgroup.com

Reason Behind this Error Database Availability Group Must Have Quorum

There are various reason or causes because of which this error occurs. Some of the reason are given below:

1. Power Outage
2. Storage space issue
3. Corruption or Malware attack
4. Human error
5. Failure of hardware
6. Update gone incorrect, etc…

Solution to Fix the Error: Database Availability Group Must Have Quorum

Users have to remove all the database copies by using the Exchange PowerShell Remove-DatabaseAvailabiltyGroupServer cmdlet. In this command they have to use the -ConfigurationOnly parameter and remove the Exchange mailbox server from the Database Availability group. This command also clear the DAG entries from the Active Directory but it will not remove the DAG member from the real cluster. That you have to do manually.

Remove-DatabaseAvailabilityGroupServer -ConfigurationOnly -MailboxServer SRV-MBEX-02 -Identity DAG3

Then, users have to evict the DAG member but this cannot be done by using the cluster manager. For this you have to use the PowerShell by using the cmdlet give below:

Get-ClusterNode “name_of_the_server” | Remove-ClusterNode -Force

If the DAG is made of two or more than that server then users have to perform this command for every node in the cluster

Get-ClusterNode Node1 | Remove-ClusterNode -Force

Get-ClusterNode Node2 | Remove-ClusterNode -Force

When the DAG memebers are removed successfully and it does not have any configuration left in the Active directory. Then the database will mount as the stand-alone server. After rebooting the server, mount the database when its clear from DAG membership.

What to do if the Database is Still Not Mount?

If your mailbox database is not mounting then you can use the Exchange Server native tool i.e. ESEUTIL utility to check the states of Exchange database. This tool easily identifies the issues and fix the Exchange database corruption.

You can use the eseutil /mh to check the database state. If the mailbox database is in the clean shutdown state then it is a healthy database and if it is in Exchange dirty shutdown state then users have to repair it.

Output

Users can perform soft recovery and hard recovery via ESEUTIL to repair EDB file. Use the eseutil /r cmdlet for soft repair and for hard repair use the eseutil /p command to bring back the database into clean shutdown state. Using this solution also leads to data loss and also you cannot predict that how much data is lost.

So, in order to repair Exchange mailbox with no loss of data, users can use the third-party software i.e. SysTools Exchange Server Recovery Tool. It easily resolves database corruption Exchange 2010 / 2013 / 2016 automatically. The tool provides Quick and Advance scan mode option which removes corruption from offline/dimounted Exchange database file. Users can this automated utility to extract mailbox from EDB file Exchange 2016/2013 and export into the Live Exchange Server, Office 365 and multiple file formats in a simplified manner.

Bringing It All Together

The write-up provides complete information to fix the database availability group must have quorum error by using the solution provided here. Now users can use the solution and solve the issue. To avoid the complexity to repair severely damaged / unhealthy / corrupted mailbox database with no data loss, for that you can use the advanced software described in the above solution instead of manual one.