Creating RDM associated with a LUN on the SAN

Hi all,

I'm asked to move machines from one ESXi to others without moving disks that reside on the NAS. The link between the virtual disk and the iSCSI target is a RDM file.

I'd like to do this from the command line of the VMhost.

I found this

http://serverfault.com/questions/105652/assign-and-remove-multiple-luns-from-vms-on-esxi-4

Is it still valid?

Basically what I understand is that I have to use vmkfstools and once I have the filename I can refer to it in the vmx file, am I right?

Thanks Alex