An NFS client built into ESXi uses the Network File System (NFS) protocol over TCP/IP to access a designated NFS volume that is located on a NAS server. The ESXi host can mount the volume and use it for its storage needs. vSphere supports versions 3 and 4.1 of the NFS protocol.

Typically, the NFS volume or directory is created by a storage administrator and is exported form the NFS server. The NFS volume is not required to be formatted with a local file system, such as VMFS. You can mount the volume directly on ESXi hosts and use it to store and boot virtual machines in the same way that you use VMFS datastores.

In addition to storing virtual disks on NFS datastores, you can use NFS as a central repository for ISO images, virtual machine templates, and so on. If you use the datastore for ISO images, you can connect the virtual machine's CD-ROM device to an ISO file on the datastore and install a guest operating system from the ISO file.

ESXi supports the following storage capabilities on most NFS volumes:

  • vMotion and Storage vMotion
  • High Availability (HA) and Distributed Resource Scheduler (DRS)
  • Fault Tolerance (FT) and Host Profiles
    Note: NFS 4.1 does not support legacy Fault Tolerance.
  • ISO images, which are presented as CD-ROMs to virtual machines
  • Virtual machine snapshots
  • Virtual machines with large capacity virtual disks, or disks greater than 2TB. Virtual disks created on NFS datastores are thin-provisioned by default, unless you use hardware acceleration that supports the Reserve Space operation. NFS 4.1 does not support hardware acceleration. For information, see Hardware Acceleration on NAS Devices.