Converting a VMDK to an RDM

27th March 2017
by InfiniteMonkeys

Converting a VMDK to an RDM

Ok a little strange, but sometime’s needs must. So we had a requirement to convert an existing VM from VMDK to a physical RDM.

Nice and straight forward however:

Create new LUN for the VM, in this case an 80GB LUN for the OS (the remaining disks where already RDMs).
Find the NAA indentifier for the new LUN “naa.
Find the existing VMDK path “vmfs/volumes/SRCVM folder/SRCVM_disk_1.vmdk”
Path for the RDM datastore mapping file to live post conversion “/vmfs/volumes/datastore/DSTVM/DSTVM_disk_1.vmdk”
Power down the VM.

Run the following:

vmkfstools –i vmfs/volumes/SRCVM folder/SRCVM_disk_os.vmdk -d rdmp:/vmfs/devices/disks/naa.000/vmfs/volumes/datastore/DSTVM/DSTVM_disk_os.vmdk

*For a virtual RDM conversion: -d rdm
*For a physical RDM conversion: -d rdmp

Have a cup of tea… depending on source size this can take some time!
Once complete, remove the SRC disk for the VM and add the cloned RDM as “Hard Disk 1”
Power on the VM and et viola.