That's awesome, I was hoping I might be able to find this information using vimsh, but I have not dug too deep, I just wanted to be sure it was not possible by just examing certain files before I go down the route of finding an alternative method.

Is the command specific to 3.0.x or 3.5? I know there's been some updates for vimsh on ESX 3.5 that do not exist in 3.0.2. I assume "32" is the vmid?

It hasn't actually, haven't had too much time looking into it. We don't use RDM extensively and we have dedicated LUNs, I know at other locations it may be nice to have but I just haven't found an easy way of finding out whether it's an RDM or normal disk. I would love to hear if anyone else has looked at this, but I get the impression it isn't sought after to know which VMs are using RDMS, most peolpe have an idea which VMs are using RDMs.

First off, thanks to sthoppay_wipro for finding this method of locating RDM information other than using the VIC, I had not thought about checking out "device.getdevices". I've gone ahead and taken that idea and came up with a quick/dirty script that can run on both ESX 3.5+ and ESXi (requires SSH Console) and loops through all virtual machines and printing out the ones that contain an RDM (Raw Disk Mapping). This task was motivated by Duncan's earlier post about locating virtual machines that contain RDM, but that solution would require a Windows system and powershell. I know this was a task I had for another project and it would be nice to have few other options.

The output will contain:
Virtual Machine Name
VM's Hard Disk Label for the RDM
VM's Datastore + it's VMDK
LUN UUID
LUN #
Compatibility Mode (Phys/Virt)
Disk Mode
RDM Size (in GB)

You can find the script at:

http://www.engr.ucsb.edu/~duonglt/rdm/

For some reason the format output is slight off on ESXi, I assume its just the limited Busybox toolset compared to the full blown RHEL SC.