Monday , November 9 2020

Database availability group must have quorum error

Decommissioning set of old Exchange 2013 servers had to export few mailboxes and
decommission them.But mailboxes are not mounting saying quorum not found. but for me the simplest way is to remove the Database Availability group completely and mount the databases and take the required data out via pst and decommission the same. So this might not be suitable for all scenarios.


Failed to mount database "MDB03". 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: MBEX01.azure365pro.com]
+ CategoryInfo : InvalidOperation: (MDB03:ADObjectId) [Mount-Database], InvalidOperationException
+ FullyQualifiedErrorId : [Server=MBEX02,RequestId=c41e871c-49e5-4a78-877f-51738b965ee1,TimeStamp=6/2/2020
6:11:51 AM] [FailureCategory=Cmdlet-InvalidOperationException] 7E29F70A,Microsoft.Exchange.Management.SystemConfig
urationTasks.MountDatabase
+ PSComputerName : mbex02.azure365pro.com

Removed all the Database Copies.

Using the configuration only switch and removed the mailbox servers from the DAG.
So that it will clear the DAG related entries from active directory.But this will not remove the dag member from real Cluster. Which we have to manually.

Remove-DatabaseAvailabilityGroupServer -ConfigurationOnly -MailboxServer SRV-HO-MBEX02 -Identity DAG2

As its a IP Less DAG,We cannot use the cluster manager to evice them. You got to use powershell.
To Evict the DAG Members.

Get-ClusterNode Node1 | Remove-ClusterNode -Force
Get-ClusterNode Node2 | Remove-ClusterNode -Force

Once the DAG Members are removed and it doesn’t have configuration on active directory. Now the databases will try to mount as a stand alone server.On reboot Databases mounted without DAG membership.

Now removed the DAG. using below commands. I have done the same steps when the cluster is completely messed up and none of the recovery options worked and we had to bring up the databases stand alone without DAG membership. Unless you understand the environment completely and don’t use this procedure without proper understanding of clusters and DAG attributes stored on Active Directory. It may cause real Damage to the environment.

About Satheshwaran Manoharan

Satheshwaran Manoharan is an Microsoft Office Server and Services MVP , Publisher of Azure365pro.com. Specialized in Office365 / Microsoft Exchange / Virtualization , Sathesh is an Messaging Expert supporting/Designing/Deploying many medium size businesses to large enterprises when it comes to Corporate messaging and Virtualization Infrastructure

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One comment

  1. this is my situation, is this the same that you describe above? how do I recover?

    Cannot mount Exchange 2010 database after DAG member failed – Active Database cannot mount
    Great Morning All!!

    I have a Exchange 2010 DAG
    (3) servers

    ProdMB – mailboxes
    ProdHTCA – Hub Transport and Client Access – also Witness Server
    DRHTCAMB – Disastery Recovery – Mailboxes, Hub Transport, Client Access

    whenever DRHTCAMB shuts down, email doesn’t work

    Currently I have a System Board that Failed on DRHTCAMB and this server is temporarily out of commission. (waiting for replacement parts)
    3 databases display “service down”

    I cannot mount the three databases on ProdMB even though this server houses the Active Databases.
    3 databases display “dismounted”

    this began with the shutdown of all systems to replace UPS batteries
    I did suspend copy first
    I did shut down the two PROD systems first
    I did then shut down the DR server

    when trying to mount the databases on ProdMB,
    I get the following error message

    Microsoft Exchange Error

    Failed to mount database ‘DBA-L’.

    DBA-L
    Failed
    Error:
    Couldn’t mount the database that you specified. Specified database: DBA-L; Error code: 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: Server ‘ProdMB’ isn’t in the stopped or started servers list. This may be due to an Active Directory replication delay.. [Server: ProdMB.domain.com].

    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: Server ‘ProdMB’ isn’t in the stopped or started servers list. This may be due to an Active Directory replication delay.. [Server: ProdMB.domain.com]

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