We've had many Win2003 VMs on our Nimble datastore and there is no conflict I'm aware of. Filesystem quiescing happens entirely within VMware anyway, so the underlying storage shouldn't be of concern.
The way I understand it is filesystem quiescing happens by having the ESXi host ask VMtools to quiesce the guest. VMtools in turn asks the guest operating system to do this (on Windows this is the Volume Shadow Service) and the guest OS will then ask all registered quiescers (is that a word?) to get ready for the snapshot. Once the registered quiescers all approve or after a timeout, the filesystem is quiesced, VMtools notifies the host and the host creates the snapshot. This snapshot is stored as a set of extra files in the datastore with the VM which any underlying storage system will handle without blinking.
I'll also add that quiescing is optional. If the guest OS doesn't support it or VMtools isn't installed, it just won't happen. In fact when you take snapshots, you have to explicitly request it. If you're concerned about a vMotion from an old datastore to Nimble triggering this, don't worry, vMotion doesn't use filesystem quiescing. It can't since not all VMs will be able to do it.
Hope this helps.
Id like to move all my old VM's to my Nimble VMFS datastore, one of those VM's is running Windows Server 2003R2
My question is the following: Will i encounter problems with the VM when quenching happens to the datastore when snapshots are being taken? I am worried that the VM might get corrupted if the OS does not support quenching? does anynone else have expierence with Windows Server 2003R2 VM's running on a nimble VMFS volume with quenching enabled for snapshotting?.