Virtual disk 'Hard disk 3' is a mapped direct-access lun that is not accessible

[greendxr]

I'm currently in the process of upgrading our ESX cluster from 4.0 U1 to 4.1. In the process I ran into a 2 server MSCS cluster with Physical RDMs. I shut down the VMs and can vmotion them between the 4.0 hosts. Now once I upgrade hosts to 4.1 I can no longer vmotion these VMs to those 4.1 hosts. The error that I get is: "Virtual disk 'Hard disk 3' is a mapped direct-access lun that is not accessible". I found a KB article http://kb.vmware.com/kb/1016210

that is talking about making sure that LUN numbers are the same in presentation to all ESX hosts and I verified this to be the case, besides like I said vmotions still does work for the hosts I haven't upgraded yet. I have not yet attempted to unpresent all LUNs and re-present them, not sure if I should try that. Looking for suggestions.

Thanks,
greendxr

[AndreTheGiant · Accepted solution]

You have to poweroff the node, remove the RDM disks, migrate the VM and then re-add again the RDM disk.

RDM LUN must be presented on all hosts.

Andre

[greendxr]

Thanks. Still not sure what caused this in the first place. Once I removed all RDMs I re-added them on the first host. Then was able to add to the second host. One thing that was confusing was that after I re-added RDMs to the first host vmdks that were created were new and at first I added the old (original) vmdks to the second host which prevented the host from powering up.