NFS is a network filesystem that provides file-level storage using the NFS protocol over an IP network. It can work in use cases similar to iSCSIthe difference being that NFS devices are presented as file systems rather than block devices. The figure below shows an NFS file system that has been exported from a network-attached server and mounted by the ESXi nodes in the VxRail environment.
Figure 64. Network-attached file system with VxRail
This enables data mobility into and between VxRail environments as well as enabling additional storage capacity.
The external NFS server can be an open system host, typically Unix or Linux, or a specially built system. The NFS server takes physical storage and creates a file system. The file system is exported and client systems, in this example ESXi hosts in a VxRail system, mount the file system and access it over the IP network.
Similar to iSCSI, NFS is a standard vSphere feature and is configured using the vCenter web client. This is done in the Hosts and Clusters view under Related Objects and the New Datastore dialog. Select NFS as datastore type, the NFS version, the name of the datastore, the IP address or hostname of the NFS server that exported the filesystem, and the host that will mount it. The NFS filesystem will appear like the vSAN datastore. VMs, templates, OVA files, and other storage objects can be easily moved between the NFS filesystem and the vSAN datastore using vMotion.
As with iSCSI, NFS works best in network environments that provide consistent and predictable performance. The network requirements for NFS should be considered when initially planning the network requirements for VxRail environment.