Adding RDMs to second node of MCSC (W2K3) Virtual Machine Nodes Across Physical Hosts
Couldn't find any other thread on this
When adding RAW disks to the second node in Cluster Virtual Machines Across Physical Hosts / Cluster Across Boxes,
VMware says point shared storage disks to the same location as the first node’s shared storage disks*
-Select Use an existing virtual disk...
-In Disk File Path, browse to the location of the (quorum) disk specified for the first node
-Select the same virtual device node you chose for the first virtual machine’s shared storage disks, ie SCSI (1:0)…
In other words to add the RDMs to mscs-node2, browse to /vmfs/volumes/lun1/mscs-node1/ mscs-node1_2.vmdk (mscs-node1_2-rdmp.vmdk)
For years we have directly added the RDMs to the second node specifying RDM not existing disk, typically we have to do this directly from the host, not the vCenter, it seems to work fine.
So what’s the safest way, the official method can cause all sorts of problems if you need to deregister RDMs on the first node (here is where I didn’t find any official docs.)
Do you delete or keep the descriptor file? We tried keeping it but ended up with multiple mappings to the .vmdk/rdmp.vmdk, so now this system has disk2_.vmdk/ disk2_-rdmp.vmdk and disk4_.vmdk/ disk4_-rdmp.vmdk pointing the same RAW.
What really worries me is safety, these are very important boxes, I’d prefer to continue having the vmdks and rdmp.vmdk in separate datastores, and not have this reliance on the primary node
Feedback please, are we the only visualization shop configuring MSCS clusters with separate RDM paths, and are there risk associated with this?
*Ref: ‘Setup for Failover Clustering and Microsoft Cluster Service - 4.1’