VMware RDM requirements for Replication Manager

I have Replication Manager 5.2.3 (with VMware proxy license) along with ESX 4 and a Celerra with Dart 5.6. I want to use RM to take a snapshot of a VM - or rather, the VMFS volume where the VM system drive resides as a VMDK file - and also a snapshot of a data drive presented as an RDM to the VM. I am using iSCSI to connect ESX to the Celerra LUNs.

The question is, what software is required on the VM in order to take a snapshot of the RDM LUN? The admin guide suggests I need the Microsoft iSCSI initiator, but do I also need an RM agent installed in the VM? Also, as a Celerra is not aware of consistency groups, how can I make sure the snapshot of the VMFS volume where the VM's system volume VMDK is located, and the snapshot of the RDM LUN occur at the same time, to ensure consistency?

Also, I assume the ISCSI initiator on the VM needs to be logged in to the Celerra target, but does it also need to be masked to the LUN that is already presented to the VM as an RDM? If so, that would make the disk show up twice.

It would be great to hear from someone who has done this successfully, as I find the RM documentation a bit vague on this topic.

Thanks,

Andreas