Yes, I have a question. Say you have a 5.1 environment with multiple hosts and a SAN. You have an RDM obviously over the 2TB limit, lets say 5TB. You just upgraded vCenter and your hosts to 5.5. So how do you convert or migrate your RDM to a standard VMDK now that VMDK's in 5.5 allows up to 62TB?
Thanks,
Rich
It depends on if you are using a pRDM or a vRDM. Here is an article explaining what you want I think.
VMware KB: Migrating virtual machines with Raw Device Mappings (RDMs)
It looks like this which came from the article you linked in a nutshell works:
"When performing a cold migration of a virtual machine with RDMs attached to it, the contents of the raw LUN mapped by the RDM are copied into a new .vmdk file at the destination, effectively converting or cloning a raw LUN into a virtual disk. This also applies when the virtual machine is not moving between ESX hosts. In this process, your original raw LUN is left intact. However, the virtual machine no longer reads or writes to it. Instead, the newly-created virtual disk is used"
So that tells me that if I do this, then once the migration creates a new VMDK file on a separate LUN on my Dell 322i SAN, and data is verified through the VM looking into the contents of the VMDK file (drive letter), then the old RDM LUN can be revamped/reused for standard storage usage. I would do this because with the new 62TB in 5.5 as opposed to the limited 2TB in recent previous versions, I would no longer need any RDM's for a very long time since there is no way I would ever need 62TB's of space for one VMDK file, maybe 3-5TB's tops. I assume the migration automatically selects the latest VMFS-5 since there is no direct option for this in a cold migration using vCenter - but there is in the Standalone Converter.
Once you do the conversion then yes basically that RDM is unmapped from your VM and the VMDK takes it's place. I would make sure all my datastores were VMFS-5 after upgrading to take full advantage.
That's a good suggestion regarding the VMFS-5 datastores.
