As part of an Always On Availability Group for SQL 2012 that was being built for a SharePoint 2013, the following error was occurring when trying to create a Windows Failover Cluster :

 

Digging a bit deeper into the Storage issue revealed the speed bump:

List Potential Cluster disks kept failing.

And another symptom was the disk on the failing server, kept going offline and sending my SQL into a whirlwind spin of chaos as the disk contained TempDB databases and logs.

Multiple disks with the same identifier

Ah ah. The underlying OS has been ofcourse created on Vmware esxi 5.1 using vm templates and as part of the template are the data disks been provisioned. For the same reason these disks weren’t getting a unique identifier. This was further identified by the following:

 

SQLAAG1 had

SQLAAG2 had

 

Both servers had the same disk ID : AF8EE961.

The culprit was that when I created these VM’s on my VMware Esxi platform, I had used a VM Template. This meant, the disks were getting the same ID. The solution to the problem , was to delete the two disks and create new ones that were joined back to the VM’s and they were happy post the fix.

 

Cheers