Raw Device Mapping option in the vSphere Client is grayed out
search cancel

Raw Device Mapping option in the vSphere Client is grayed out


Article ID: 343335


Updated On:


VMware vSphere ESXi


This article provides information on why the Raw Device Mapping (RDM) option is grayed out.

  • You cannot create a Raw Device Mapping (RDM).
  • If you connect the vSphere Client directly to an ESXi host, the Raw Device Mappings option is grayed out.

    Note: To access the Raw Device Mappings option, right-click the virtual machine and click Edit Settings > Add Hard Disk > Raw Device Mappings.
  • If you navigate to Configuration > Storage adapters, you cannot see LUNs that are not used as VMFS volumes.
  • If you navigate to Configuration > Storage > Add storage > Disk/LUN, you cannot see LUNs available in the list.


VMware vSphere ESXi 5.1
VMware vSphere ESXi 6.5
VMware vSphere ESXi 6.0
VMware ESXi 4.1.x Embedded
VMware vSphere ESXi 5.5
VMware vSphere ESXi 6.7


The Raw Device Mapping (RDM) option is grayed out if:
  • Your storage type does not support RDMs. For more information, see the Comparing Types of Storage section of the vSphere Storage Guide.
  • There are no available LUNs to be presented to an ESXi host. They may have already been committed to storing VMFS or have already been mapped to other virtual machines as RDMs.
  • The vCenter Server has an older cache of known devices which can be used for RDMs, not including the intended LUN. Rescan your storage to pick up the changes. For more information, see Performing a rescan of the storage on an ESXi host (1003988).
  • You are using a SAS Direct Attached Storage (DAS) array that is being detected as Local Storage. For more information, see Raw Device Mappings for Local Storage (1017530).
  • You are using an external shared SAS storage array like the Dell MD32xx. This requires that the checkbox RdmFilter.HbaShared is deselected in order to use a LUN as RDM. This is expected behavior because the RDM filter only applies to Fiber Channel, FCoE and iSCSI.

Additional Information

Raw Device Mapping for local storage