Error – The Cluster Service Cannot Be Started. An Attempt To Read Configuration Data From Windows Registry Failed With Error ‘2’.

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

Source:        Microsoft-Windows-FailoverClustering

Event ID:      1090

Task Category: Startup/Shutdown

Level:         Critical

User:          SYSTEM

Computer:      EX01.HEW.LOCAL

Description:

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.

1. 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.
2. Try a force cleanup of the cluster from the failed server. Run Cluster Node “ServerName” /forcecleanup from an elevated command prompt.
3. 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”.