Steps to add Pass-through Disk in Highly Available VM –  2012R2

  • Shutdown VM if it is powered on (Best Practice)
  • Make Sure Disk is online at HOST level and note down Disk Number
  • Go to Failover Console -> Add Disk to cluster ->After adding it will be placed in “Available Storage” ->Note the Disk number in console for later verification
  • Check whether Disk owner in failover console is displaying current working Server or not , else you need to proceed all steps by logging to the disk owner server.
  • In Failover Console ->Under Disk’s  section -> Right Click Disk ->  Assign to VM Role-> Select the VM which for which you want to assign.
  • After adding the disk to Failover Cluster, assign it to the VM role and ensure that the disk is online on HOST. If it is offline when you perform the remaining steps, the disk will be Read-Only in the VM with no way to fix it but to start over
  • In Failover ->Roles -> Go to VM -> Check under Resources Section -> Under Virtual Machine-> “Virtual Machine Configuration”  resource should online
  • In failover Console -> Go to VM Settings ->Add virtual SCIS adapter -> Pass Through Disk 4
  • Start VM ->Check Disk is accessible or not
  • Test Live Migration  

In 2008 or 2008 R2

DISK should be offline at HOST else it will go in READ-ONLY MODE  -> Blogs confirmed the same and I too seen the same issues

A new disk must be brought Online and Initialized before it can be used. This process writes a disk signature to the disk so cluster can use it. Once the disk has been initialized, it can be placed Offline again. No partitioning is required as that will be accomplished inside the virtual machine

Difference between adding pass-through disk in 2008 & 2012 is -> In 2008, Disk should be initialized and make offline whereas in 2012 it should be online throughout  the process