Hi,
I have studied the cluster PDF documentation for setting up MS clusters. However this question has nothing to do with MS clusters.
I would like 2 VMs using linux+heartbeat accessing a common disk device (only one node at a time). Each VM has its own vmdk file (exosed inside the guest as /dev/sda). I can create a RDM mapping using the GUI or vmkfstools --createrdm /vmfs/devices/disks/... for each of the VMs to be exposed inside the guest as /dev/sdb)
I can attach as an existing disk the raw device mapping and define it to be virtual instead of physical. If it is physical, the vmware snapshots do not work (I need that), so I choose virtual instead.
However, now comes the problem: what about the SCSI Bus Sharing setting. If you keep them at None, then both machine appear to be able to access the common device (shows up as /dev/sdb in the guest) and you can do vmware snapshots (of course I specially define the common device not to be part of snapshots, i.e. independent).
If you set the Bus Sharing to Physical (if you run the VMs on 2 different hosts, which I do), then you cannot do snapshots, because:
VMControl error -999: Unknown error: SoapError: ServerFaultCode(1978) : (Virtual machine is configured to use a device that prevents the snapshot operation: Device '' is a SCSI controller engaged in bus-sharing.)
Why is it possible to choose SCSI Bus Sharing: None against an RDM device from 2 virtual machines, what does that do or violate when the VMs are powered on?
I would like to be able to snapshot the base OS from the actual 12GB VMDK disk file that is part of the VM (and exposed inside the guest as /dev/sda).
Steffen
