Sharing virtual disks amongst multiple vm's requires a disk manager or cluster manager to control access to that disk. When you share a disk, each server thinks it is the sole owner of that disk, and writes to it accordingly. As soon as you mount that same disk from another virtual machine, that vm will see the data on the disk, but no newly written data that other virtual machines will write to that disk. Since each server is unaware of any other server which may be modifying data on that disk, there is a very large disk/data corruption risk. This is why you need some kind of a clustering solution (Microsoft clustering), to manage access to that disk. MSCS will control access to that disk, but again, only one server will have access to that disk at any one time. NTFS is not a cluster filesystem, so it can't handle multiple servers writing to it at the same time. You will be better served by sharing that disk from one host, and mounting/mapping that share from any other server that needs access to that disk.
-KjB
VMware vExpert
vExpert/VCP/VCAP
vmwise.com / @vmwise
-KjB
