If your deployment includes NAS devices that support the vStorage APIs for Array Integration (VAAI), you can enable the View Composer Array Integration (VCAI) feature on linked-clone pools. This feature uses native NFS snapshot technology to clone virtual machines.
With this technology, the NFS disk array clones the virtual machine files without having the ESXi host read and write the data. This operation might reduce the time and network load when virtual machines are cloned.
Apply these guidelines for using native NFS snapshot technology:
You can use this feature only if you configure desktop pools on datastores that reside on NAS devices that support native cloning operations through VAAI.
You can use View Composer features to manage linked clones that are created by native NFS snapshot technology. For example, you can refresh, recompose, rebalance, create persistent disks, and run QuickPrep customization scripts on these clones.
You cannot use this feature if you store replicas and OS disks on separate datastores.
This feature is supported on vSphere 5.0 and later.
If you edit a pool and select or deselect the native NFS cloning feature, existing virtual machines are not affected.
To change existing virtual machines from native NFS clones to traditional redo log clones, you must deselect the native NFS cloning feature and recompose the pool to a new base image. To change the cloning method for all virtual machines in a pool and use a different datastore, you must select the new datastore, deselect the native NFS cloning feature, rebalance the pool to the new datastore, and recompose the pool to a new base image.
Similarly, to change virtual machines from traditional redo log clones to native NFS clones, you must select a NAS datastore that supports VAAI, select the native NFS cloning feature, rebalance the pool to the NAS datastore, and recompose the pool.
On an ESXi cluster, to configure native cloning on a selected NFS datastore in View Administrator, you might have to install vendor-specific NAS plug-ins that support native cloning operations on VAAI on all ESXi hosts in the cluster. See your storage vendor documentation for guidance on configuration requirements.
Native NFS snapshot technology (VAAI) is not supported on virtual machines with space-efficient disks. VAAI is not supported on machines that are virtual hardware version 9 or later, because these OS disks are always space-efficient, even when you disable the space reclamation operation.
This feature is not available if you use a Virtual SAN datastore or a Virtual Volumes datastore.
See VMware Knowledge Base (KB) article 2061611 for answers to frequently asked questions about VCAI support in View.
NAS storage vendors might provide additional settings that can affect the performance and operation of VAAI. You should follow the vendor's recommendations and configure the appropriate settings on both the NAS storage array and ESXi. See your storage vendor documentation for guidance on configuring vendor-recommended settings.