Error received when trying to add an RDM to a VM or expand a VMDK of a VM that has an RDM attached that resides on vSAN or vVOl

Products

• VMware vSAN
• VMware vSphere ESXi

Issue/Introduction

• VM resides on vSAN or vVol
• When trying to add an RDM to the VM or expand one of the VMDKs attacjed to the VM it fails with one of the below errors
  "Incompatible device backing specified for device '0'."
  A general system error occurred: PBM error occurred during PreReconfigureCallback: Fault cause: pbm.fault.PBMFault ; Error when trying to run pre-provision validation; Invalid entity
• In /var/run/log/hostd.log you see below:
  [YYYY-MM-DDTHH:MM:SS] error hostd[2101830] [Originator@6876 sub=Vdisksvc opID=lq7e4eth-#######-auto-1kg1m-h5:70887696-4-01-19-fef2 user=vpxuser:ORA-ITMCLOUD.NTTDATA.LOCAL\Administrator] ValidateDiskDevice: Invalid datastore vsan:5245c7451fb9cf7d-b7d5############ specified.
  [YYYY-MM-DDTHH:MM:SS] info hostd[2101830] [Originator@6876 sub=Vmsvc.vm:/vmfs/volumes/vsan:5245c7451fb9cf7d-b7d5############/6332b067-3651-5abd-9ad1-############/VM-Test.vmx opID=lq7e4eth-#######-auto-1kg1m-h5:70887696-4-01-19-fef2 user=vpxuser:ORA-ITMCLOUD.NTTDATA.LOCAL\Administrator] ValidateRawDiskDevice: Rdm device is not supported
  
  Note: You will see similar messages regarding vVols as well

 

Environment

VMware vSAN (All Versions)

vSphere ESXi (All Versions)

Cause

RDMs are not supported for VMs that reside on vSAN or vVols

Limitations of vSAN

Virtual Volumes Limitations

Resolution

• If an RDM is required for use with the VM, migrate the VM to a VMFS datastore if possible.
• If the VM can't be migrated to a VMFS datastore, you will need to convert the RDM to a VMDK.