When using NFS storage, you must follow specific configuration, networking, and NFS datastore guidelines.
NFS Server Configuration Guidelines
- Make sure that NFS servers you use are listed in the VMware HCL. Use the correct version for the server firmware.
- When configuring NFS storage, follow the recommendation of your storage vendor.
- Ensure that the NFS volume is exported using NFS over TCP.
- Make sure that the NFS server exports a particular share as either NFS 3 or NFS 4.1, but does not provide both protocol versions for the same share. This policy needs to be enforced by the server because ESXi does not prevent mounting the same share through different NFS versions.
- NFS 3 and non-Kerberos NFS 4.1 do not support the delegate user functionality that enables access to NFS volumes using nonroot credentials. If you use NFS 3 or non-Kerberos NFS 4.1, ensure that each host has root access to the volume. Different storage vendors have different methods of enabling this functionality, but typically this is done on the NAS servers by using the no_root_squash option. If the NAS server does not grant root access, you might still be able to mount the NFS datastore on the host. However, you will not be able to create any virtual machines on the datastore.
- If the underlying NFS volume, on which files are stored, is read-only, make sure that the volume is exported as a read-only share by the NFS server, or configure it as a read-only datastore on the ESXi host. Otherwise, the host considers the datastore to be read-write and might not be able to open the files.
NFS Networking Guidelines
- For network connectivity, the host requires a standard network adapter.
- ESXi supports Layer 2 and Layer 3 Network switches. If you use Layer 3 switches, ESXi hosts and NFS storage arrays must be on different subnets and the network switch must handle the routing information.
- A VMkernel port group is required for NFS storage. You can create a new VMkernel port group for IP storage on an already existing virtual switch (vSwitch) or on a new vSwitch when it is configured. The vSwitch can be a vSphere Standard Switch (VSS) or a vSphere Distributed Switch (VDS).
- If you use multiple ports for NFS traffic, make sure that you correctly configure your virtual switches and physical switches. For information, see the vSphere Networking documentation.
- NFS 3 and non-Kerberos NFS 4.1 support IPv4 and IPv6.
NFS Datastore Guidelines
- To use NFS 4.1, upgrade your vSphere environment to version 6.x. You cannot mount an NFS 4.1 datastore to hosts that do not support version 4.1.
- You cannot use different NFS versions to mount the same datastore. NFS 3 and NFS 4.1 clients do not use the same locking protocol. As a result, accessing the same virtual disks from two incompatible clients might result in incorrect behavior and cause data corruption.
- NFS 3 and NFS 4.1 datastores can coexist on the same host.
- vSphere does not support datastore upgrades from NFS version 3 to version 4.1.
- When you mount the same NFS 3 volume on different hosts, make sure that the server and folder names are identical across the hosts. If the names do not match, the hosts see the same NFS version 3 volume as two different datastores. This error might result in a failure of such features as vMotion. An example of such discrepancy is entering filer as the server name on one host and filer.domain.com on the other. This guideline does not apply to NFS version 4.1.
- If you use non-ASCII characters to name datastores and virtual machines, make sure that the underlying NFS server offers internationalization support. If the server does not support international characters, use only ASCII characters, or unpredictable failures might occur.