Fail to create RDM with "Incompatible device backing specified for device '0'."

Products

• VMware vSphere ESX 7.x
• VMware vSphere ESX 8.x

Issue/Introduction

Symptoms:

• Adding an RDM LUN to a node fails.
• You see this error:
  
  Incompatible device backing specified for device '0'
• In the /var/log/hostd.log file, you see entries similar to:
  
  [YYYY-MM-DDTHH:MM:SS] info hostd[2101830] [Originator@6876 sub=Vmsvc.vm:/vmfs/volumes/########-########-####-############/VMname/VMname.vmx opID=########-#-##-##-#### user=vpxuse] ValidateRawDiskDevice: Rdm device is not supported
[YYYY-MM-DDTHH:MM:SS] warning hostd[2101830] [Originator@6876 sub=Vmsvc.vm:/vmfs/volumes/########-########-####-############/VMname/VMname.vmx opID=########-#-##-##-#### user=vpxuser] Exception thrown during reconfigure: (vim.vm.ConfigSpec) {
.....

        -->             capacityInKB = 2411725440,
        -->             capacityInBytes = 2469606850560,

Environment

VMware vSphere ESXi 7.x

VMware vSphere ESXi 8.x

Cause

RDM disk larger than 2TB is only supported on VMFS datastores (VMFS5 and higher versions).

Resolution

Reduce RDM to less than 2TB(2*1024*1024*1024*1024).