Error: Two disks have been found on node node1 that cannot be distinguished from one another

I was trying to create a failover cluster in Windows Server 2012 R2 (Creating a Windows Server 2012 R2 Failover Cluster using StarWind iSCSI SAN v8) and I ran the “Validate Configuration…”.  Once validation was complete, the validation report gave me the Error:

Two disks have been found on node node1 that cannot be distinguished from one another. The disks involved have disk signature <Signature>, SCSI page 83h VPD descriptor <GUID>, SCSI page 80h VPD Serial Number <Serial Number>. Please verify the storage configuration. You must either mask (unpresent, detach) one of these LUNs at this node, or, run validation and specify a disk list that includes only one of these disks, for example by using the Test-Cluster cmdlet in Windows PowerShell

After searching all over, I finally found an article that pointed me in the right direction:

Windows Server 2012 / 2008R2 with iSCSI error 80 or 83 VPD[http://culmor.blogspot.com/2013/03/windows-server-2012-2008r2-with-iscsi.html]

This article didn’t have my fix, but it did state that “The error probably relates to your MPIO configuration”.  That’s when I found two listings in my iSCSI Initiator’s Favorite Targets screen.  I removed one of the listings and bam!…Error gone.

iSCSI.FavoriteTargets

 

The issue for me turned out to be that I had multiple virtual adapters (vNICs) that pointed to the SAN provider.  By removing one of them, it removed the duplicate SAN devices.