SVMotion with RDM's

[Natsidan]

When using Svmotion what happens to the RDM lun that is attached to the Vmdk file. I understand that the RDM is mapped by a Lun mapping file but I used SVMotion to move a vmx file and selected all vmdk files to be re located. When this had finshed there was a 12gb RDM lun attached to the vmdk file and it used the total space out of that datastore for the vmdk file and RDM file of 42GB 30 for OS and 12 for RDM file?

I want to SV motion OS disks tomorrow with 500GB rdm luns attached what will happen??.

I have looked in the datastore before moving the said vmdk files and the rdm luns if highlighted show a size of 1,000 MB but the lun is only 250GB i am a little confused.

bascially what should i select just to relocate the OS vmdk file or all files?

[njd62495]

A RDM will not move to another lun. Only VMFS volumes with VMDK files.

[Natsidan]

I have just SVmotioned a VM with a RDM file attached when the copy had finished. I went to edit setttings in the VM and the second disk was now a VMDK file I had the option to enlarge the vmdk file even though it was a page file RDM uisng the full capacity of the LUN before the migration??

Is there a difference when you shut down and do a cold migration from SVmotion??.

Is Svmotion a IP copy or a SAN copy is the VC server involved at all?

[jmp8600]

sidanat,

it uses SAN to copy data.

Are you saying that ur 500gb rdm converted to 500gb vmdk? this doesn't make any sense.

-jp

[jagripino]

I just happened to me too, although with much smaller RDM LUNs, so I can vouch for it. VMware says the SVMotion handles the RDM correctly (that is, moves the .vmdk files that point to the LUNs and updates then, but does not move the data), so right now we suspect an issue with the SVMotion plugin.

Very weird indeed, and it broke a couple of servers for me

[mike_laspina]

Hi,

SVmotion does not move RDMs. In the best case it does create a compatible mode vmdk to point to the RDM however if the RDM LUN is not SAN mapped at the host receiving the VM with the same LUN number the VM will fail to access the RDM until that is corrected.

There are too many security problems with RDM mapping changes and this is one of the reasons I don't use RDMs.

Best bet is to use vConverter to move it to a VMFS based store and avoid RDMs. They do not provide much advantage unless your using SAN based snapshots for point in time recovery.

Regards,

Mike

vExpert 2009