I'm trying to set up a two node cluster with Windows Server 2012 and ESXi 5.5. What I want to know is this: Can I use VMDK disks for the cluster shared storage, and if so, how do I go about configuring them?
For details about the setup please take a look at VMware KB: Microsoft Cluster Service (MSCS) support on ESXi/ESX and the links provided in the KB. The type of shared disks which are supported depends on the cluster type you are going to setup, e.g. Cluster-in-a-Box.
You can use a cluster in separate hosts using VMDK.
First, create the VMs in the same host, configure and validate MSCS. The shared disks SCSI Bus Sharing have to be in Physical mode.
With the cluster OK, shutdown the VMs, create a rule affinity to separate the VMs in diferent hosts and power on the VMs.
It will works. But its probably not supported by VMware.
"VMDK disks for the cluster shared storage" is not supported because the SCSI reservation is not supported for VMDK disk and which is a requirement for MSCS cluster or else the data corruption chances is possible.