In my previous article I've given you a little hint for having shared storage between multiple VM. Can we do it without using the overhead of an iSCSI virtual machine (of physical, whatever)? I was thinking about the old days - clustering with virtual machines, creating a cluster with Microsoft Clustering Services. There you needed to create a shared resource for your quorum and data. I was thinking: "would this work if I did this for my two ESX machines. Create a shared disk, put VMFS on there and a VM. Would I still be able to VMotion it?" The answer is: Yes you can! Exciting!

How?
There are enough resources for creating a shared resource disk but here is a recap:

Make a pre-allocated virtual disk!!!
Add the following lines to both your .VMX files:

scsi1.present = "TRUE"
scsi1.virtualDev = "lsilogic"
scsi1.sharedBus = "VIRTUAL"
scsi1:0.present = "TRUE"
scsi1:0.fileName = "D:\Virtual Machines\shared_disk.vmdk"
scsi1:0.mode = "independent-persistent"
scsi1:0.redo = ""
 
disk.locking = "FALSE"
diskLib.dataCacheMaxSize = "0"
diskLib.dataCacheMaxReadAheadSize = "0"
diskLib.dataCacheMinReadAheadSize = "0"
diskLib.dataCachePageSize = "4096"
diskLib.maxUnsyncedWrites = "0"

Or just check my example of my .VMX file in my download section.

Have funn!