Virtual RDM - Increase

[godaba]

Hi All,

one of the VM has Virtual RDM's connected and need to be increase one RDM, with out shutdown the VM.

most of the forums saying VM need to be shutdown, any other ways to perform the increase with out downtime.

If we change the Disk Compatibility mode from "Virtual to Physical" will there be any impact on the Data inside RDM. 

[connecttoduy]

Hello

Yes sure. I thing we can not resizing RDM disk without downtime.

Regards,

Duy

[memaad]

Just increase disk size of RDM from storage end and rescan within guest OS for disk, this should reflect new size, then you can expand filesystem on it

[rievax]

Hi,

For Virtual RDM - yes, you will have to turn off the VM.
For Physical RDM - no, you can just expand the LUN on the storage and refresh in the VM OS.

Did that multiple times and works as expected. Beware of the 2TB limit...

KB from VMware:

• Expanding the size of a Raw Device Mapping (RDM) (1007021) (vmware.com)
• Difference between Physical compatibility RDMs and Virtual compatibility RDMs (2009226) (vmware.com)

Regarding moving from Virtual to Physical, there are no problems doing so. The opposite it also very useful when you want to convert from RDM to regular VMDK: use Virtual RDM then storage vMotion to another Datastore and you end-up with a RDM free VM....

Hope that helps.

Cheers,

R.