We have found the problem,documented here:  [URL]  basically on ESX 4 there is a bug where the lock files on the nfs datastores lock down the VM, that hangs. Resolution:  Upgrade to 4.1 OR Disable Change block tracking on the VM.
Hi,  i have a Vmware enviroment connected to NFS shares. Even taking/committing a snapshot of a very small VM with virtually no changes (delta), the process of committing takes 10-15 seconds, which is not accecpatble.  I have read the ACK could cause the problem, is it possible to disable that?  thanks Nick
VXE3150 ping lost during vmware commit on very small VMs