How to - Snapshot RDM disk in physical mode & RDM related questions.

[dewan]

Hi All,

I would like to upgrade a few production VM's hardware from version 4 to 7, so i can back them up using vDR.

One of the recommendation is to take snapshots of the required VMs prior to hardware upgrade, I am unable to do so because of RDM disk is in physical mode.

I am looking for answers of the following questions:

- How do we or can we, change RDM disk in physical to virtual mode (any risks, process involved etc..)?

- How do we dismount and mount RDM disk without loosing any data?

- Can we dismount and mount RDM disk to a different VM?

- Can we convert RDM to a normal virtual disk on vmfs datastores?

Appreciate for your time read/reply.

Ta

[Satyavmware · Accepted solution]

Hi Dewan,

Please find the answers in line.

- How do we or can we, change RDM disk in physical to virtual mode (any risks, process involved etc..)?

  Remove the RDM Disk from the VM and again Add the RDM back using virtual mode.

  (Don't select the wrong option- Remove from virtual machine and delete files from disk)

- How do we dismount and mount RDM disk without loosing any data?

Same as above. (if I understand your question correctly)

- Can we dismount and mount RDM disk to a different VM?

  Remove from VM-1 and Add to VM-2 using VM Edit Settings option.

- Can we convert RDM to a normal virtual disk on vmfs datastores?

Yes, we convert RDM to virtual disk using Migration (SVMotion). For doing the VM should be in powered off state.

Let me know this answers your queries.

Regards

Satya

[Paul11]

Here is the KB article for changing a RDM from physikal to virtual mode:

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=100659...

You should select "Delete from disk", so the mapping file will be deleted. You can not delete the RAW-device with this option, so there is no risk.

Paul

[dewan]

Thanks for your helpful answers.

[mcowger]

Note that there may be a good reason your VM had a pRDM as opposed to a vRDM.....I wouldn't change it unless you know why.