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Cannot add an RDM LUN to the second node in the MSCS cluster (2054897)


  • You cannot add an RDM LUN to the second node in a MSCS cluster.
  • Adding an RDM LUN to the second node in a MSCS cluster fails.
  • You see the error:

    Incompatible device backing specified for device ‘0’

  • The vmware.log file (located in the virtual machine directory) contains entries similar to:

    vmx| TOOLS received request in VMX to set option 'synctime' -> '0'
    vmx| VMAutomation: Hot add device. type=20, backing=100
    vmx| Requesting hot-add of scsi1
    vmx| Hot-adding scsi1
    vmx| HotPlug: Queued scsi1 add.
    vmx| HotPlug: Hot-add of scsi1 failed.
    vmx| Msg_Post: Error
    vmx| [msg.devices.hotadd.failed] Hot-add of scsi1 failed.
    vmx| [msg.devices.hotplug.errMsg] Request aborted
    vmx| [msg.devices.hotplug.failed] The hot-plug operation failed.

  • The hostd.log file (located at /var/log/) contains entries similar to:

    T14:01:39.091Z [5C736B90 error 'VdisksvcPlugin' opID=E6E3E0B7-0000063D-2] ValidateRawDiskDevice: Couldn't find the device: vml.0200010000600508b40006df850000d001cbb40000485356323030
    2013-02-12T14:01:39.091Z [5C736B90 info 'vm:/vmfs/volumes/4d2bf018-c2b733f2-700a-3c4a926c58c4/Node2/Node2.vmx' opID=E6E3E0B7-0000063D-2] SetDiskProperties: 2TB+ rdm device is not supported: (vim.vm.device.VirtualDisk)


This issue occurs if the RDM LUN ID is not the same across hosts.


When sharing MSCS RDM LUNs between nodes, ensure that the LUNs are uniformly presented across all ESXi/ESX hosts. Specifically, the LUN ID for each LUN must be the same for all hosts.
If the LUN IDs are not the same across hosts, contact your storage admin, team or storage vendor to change the LUN ID appropriately. It is a better practice to assign the LUN to a new, previously unused ID and present the LUN under the new ID to the cluster.

Reboot the appropiate hosts to ensure they pick up the LUN ID, after the RDM LUN is presented to the hosts that should see it using the new ID.

See Also

Request a Product Feature

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