Use the vmkfstools command to map a pass-through raw device to a file on a VMFS volume. This mapping lets a virtual machine bypass ESXi SCSI command filtering when accessing its virtual disk. This type of mapping is useful when the virtual machine needs to send proprietary SCSI commands, for example, when SAN-aware software runs on the virtual machine.
After you establish this type of mapping, you can use it to access the raw disk just as you would any other VMFS virtual disk.
When specifying the device parameter, use the following format:
vmkfstools -z /vmfs/devices/disks/disk_ID my_rdm.vmdk