I’ve already done a write-up of the VAAI-NAS features in vSphere 5.0, but one of the three VAAI NAS primitives has expanded functionality in vSphere 5.1.
In vSphere 5.1, the NFS File Cloning primitive is expanded to allow array-based snapshots to be used for virtual machines and vApps being fast-provisioned by vCloud Director. When vCloud Director does a fast-provision of VMs and/or vApps on a supported NAS array, VAAI-NAS File Cloning is used to off-load the clone creation to the array transparently. As with NFS File Cloning in vSphere 5.0, this feature requires a VAAI NAS plug-in from the storage array vendor.
