Adding a member to a DAG should be simple? Right? Well it can go very wrong as well.
Unique error that we encountered. The first DAG set went through fine and all stores mounted etc. however on the second pair, the server would install Failover Cluster or so it seemed and then the GUI or PowerShell command would fail to say that the service cannot be found yet it would show the cluster service under services. This is the error presented:
A few steps were taken to try and resolve this.
We firstly rebooted and then uninstalled Failover Cluster and then rebooted again.
Next was to install Failover cluster directly on the server and it resulted in the same error.
Next step was to run an SFC /scannow command on the server and it ran for 30 minutes and could not repair anything. The clusDisk.dll could not be repaired due to a hash mismatch.
Booting off the media and then running the same command failed as well.
Lastly we tried running StartRep.exe but it didn’t find anything.
So end of the day, we ended up shutting down the VM and rebuilding due to OS corruption caused by underlying hardware.
Hope it helps.