Expanding Size of RDM disk for a Virtual Machine

[Ace007]

Hello Friends,

Firstly apoligies if im posting my question in wrong container.

I need to know the best and correct procedure to increase size of an RDM disk attached to a VM as 😧 or E:Drive.

I did the expansion in below way.

1. Shutdown the VM

2. Remove the RDM disk from VM

3. Expanded the LUN from SAN side

4. Re-scan at Host HBA's to see the new size

5. Attached the RDM link to the VM again

6. Expanded the size of the disk in VM with diskpart.

It was successfull.

My Question is - Is this the only correct procedure, i mean to shutdown the vm and remove the disk from vm..

Could anyone share their experiences, best practices, any issues when doing...

Thanks in Advance.

[a_p_]

It actually depends on whether this is an RDM in physical or virtual mode.

The steps you mentioned are correct for virtual mode RDMs but may not be required for physical mode RDMs. For RDM's in physical mode you can just increase the LUN and run a rescan on the host as well as in the guest OS. However, remember that the new LUN size will not match the displayed size of the RDM anymore and - in case you want to convert/migrate the RDM to a virtual disk - you will first need to recreate the RDM mapping files, because the size information in the header file is used in this case!

see http://kb.vmware.com/kb/1007021 for details

André

[Ace007]

Thanks for your reply,,i did the steps for the RDM with Physical mode. I was not sure that this can be done without down time of the VM and without removing and re-adding the RDM to the VM.

One more thing, is there any document for best practices..