Migrate VM with physical mode RDM from 5.5 host to 6.5 host connected to new vCenter Server

[shanelovett]

Hi,

We have created a new vSphere environment alongside our existing one, consisting of 2 x ESXi 6.5 hosts & a 6.5 VCSA (vCenter Server appliance).

Our existing environment consists of 6 x ESXi 5.5 hosts & a 5.5 vCenter Server installed on a Windows box. The new VCSA & existing Windows vCenter Server have no knowledge of each other. The new hosts are connected to the VCSA, & the existing hosts are connected to the Windows vCenter Server.

Both the new hosts & the existing hosts are connected to the same fibre-channel switches, & have been zoned accordingly. Both sets of hosts can access ALL LUNs/datastores.

My scenario is this; I need to migrate a VM with a physical RDM from an ESXi 5.5 host connected to the old vCenter, to an ESXI 6.5 host connected to the new VCSA. Downtime is acceptable.

If RDMs weren't involved, then the process is very straight-forward - power down VM, remove from Inventory of existing vCenter, browse datastore in new vCenter, add to Inventory & power on VM.

Am I correct in thinking this is not as simple when dealing with a VM with a physical mode RDM? During my research there is mention of an issue with LUN IDs as per this article:

https://labs.par-tec.it/vsphere-vm-with-rdm-migration-across-virtual-datacenters/

I would appreciate any advice.

Thanks in advance

Shane

[dskwared]

My understanding is that the process is quite similar, however you would need to ensure that the physical RDM disk is also zoned/mapped to the new ESXi 6.5 host for the VM to see. Also, don't forget to tag that RDM disk as being perennially reserved on the ESXi 6.5 host(s) in the new environment to prevent long host reboots.