Hello.  If you run this command from one of the nodes: 'emcphostid check  -host clusternode1 clusternode2 clusternode '   what does it return?  Also, what's the storage array?

This is what I get

C:\Users\xenadmin>emcphostid check -host xxx001

Host: XXX001 - HostId: 0x5AA86EF1

C:\Users\xenadmin>emcphostid check -host xxx002

Host: xxx002 - HostId: 0x1EE23279

C:\Users\xenadmin>emcphostid check -host xxx003

Host: xx003 - HostId: 0x7B898449

C:\Users\xenadmin>emcphostid check -host xxx004

Host: xxx004 - HostId: 0x30E749D2

C:\Users\xenadmin>emcphostid check -host xxx005

Host: xxx005 - HostId: 0x9AFC3706

C:\Users\xenadmin>emcphostid check -host xxx006

Host: xxx006 - HostId: 0x22C149C4

C:\Users\xenadmin>emcphostid check -host xxx007

Host: xxx007 - HostId: 0x4647C9D0

C:\Users\xenadmin>emcphostid check -host xxx008

Host: xxx008 - HostId: 0xFDFD6736

Storage is EMC VMAX 10K

PS: I masked hostname

Those look good.  The command returned and the values are unique.  If you add the LUN that is failing validation to the "available storage" cluster group, or to an empty group, does it come online and can it be moved between the nodes?   If not I'd double check and make sure the PER flag is set on the LUN.  If the disk works in the cluster but validation still fails, you may need to open a support case.

Looks like we both are online. Now here is the thing, MS says "

When added more nodes, again got Disk errors in Cluster Validation.

“Failed to access sector 11 on disk with identifier fee80203 from node XXX ”

Recommended involving Storage vendor to correct the Storage configurations. PR Reservations are not cleared.

"

Storage team says "SCSI Persistence Reservation " Enabled

So do you think EMC still can look at this?