While doing a Exchange 2010 DR test, Exchange 2010 SP1 mailbox servers in the primary datacentre failed to add itself back into the DAG’s underlying cluster.
The error message I got is shown below.
Log Name: System
Event ID: 1090
Task Category: Startup/Shutdown
The Cluster service cannot be started. An attempt to read configuration data from the Windows registry failed with error ’2′. Please use the Failover Cluster Management snap-in to ensure that this machine is a member of a cluster. If you intend to add this machine to an existing cluster use the Add Node Wizard. Alternatively, if this machine has been configured as a member of a cluster, it will be necessary to restore the missing configuration data that is necessary for the Cluster Service to identify that it is a member of a cluster. Perform a System State Restore of this machine in order to restore the configuration data.
While running the Start-DatabaseAvailabilityGroup “DAG Name” cmdlet which will add the “evicted” DAG members back into the cluster, the process fails with the error above. I noticed that the cluster service was set to disabled. Trying to start it manually failed. The following steps were taken to fix the issue.
- Make sure that the cluster files are excluded in the AV scanning. If not, exclude the folder (C:\Winnt\Cluster). I tried stopping the AV service to “unlock” the cluster files.
- Try a force cleanup of the cluster from the failed server. Run Cluster Node “ServerName” /forcecleanup from an elevated command prompt.
- Once the cleanup is successful, open Failover Cluster Manager and add the failed server manually back into the cluster. You can also try running Start-DatabaseAvailabilityGroup “DAG Name” –MailboxServer “FailedServer”.