6.0.1

NFS Datastore Guidelines
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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.
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You cannot use dierent 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.
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NFS 3 and NFS 4.1 datastores can coexist on the same host.
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vSphere does not support datastore upgrades from NFS version 3 to version 4.1.
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When you mount the same NFS 3 volume on dierent 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 dierent 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.
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If you use non-ASCII characters to name datastores and virtual machines, make sure that the
underlying NFS server oers internationalization support. If the server does not support international
characters, use only ASCII characters, or unpredictable failures might occur.
NFS Protocols and ESXi
ESXi supports NFS protocols version 3 and 4.1. To support both versions, ESXi uses two dierent NFS
clients.
NFS Protocol Version 3
vSphere supports NFS version 3 in TCP. When you use this version, the following considerations apply:
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With NFS version 3, storage trac is transmied in an unencrypted format across the LAN. Because of
this limited security, use NFS storage on trusted networks only and isolate the trac on separate
physical switches. You can also use a private VLAN.
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NFS 3 uses only one TCP connection for I/O. As a result, ESXi supports I/O on only one IP address or
hostname for the NFS server, and does not support multiple paths. Depending on your network
infrastructure and conguration, you can use network stack to congure multiple connections to the
storage targets. In this case, you must have multiple datastores, with each datastore using separate
network connections between the host and the storage.
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With NFS 3, ESXi does not support the delegate user functionality that enables access to NFS volumes
by using nonroot credentials. You must ensure that each host has root access to the volume.
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NFS 3 supports hardware acceleration that allows your host to integrate with NAS devices and use
several hardware operations that NAS storage provides. For more information, see “Hardware
Acceleration on NAS Devices,” on page 265.
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When hardware acceleration is supported, you can create thick-provisioned virtual disk on NFS 3
datastores.
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NFS 3 locking on ESXi does not use the Network Lock Manager (NLM) protocol. Instead, VMware
provides its own locking protocol. NFS 3 locks are implemented by creating lock les on the NFS server.
Lock les are named .lck-file_id..
NFS Protocol Version 4.1
When you use NFS 4.1, the following considerations apply:
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NFS 4.1 provides multipathing for servers that support session trunking. When trunking is available,
you can use multiple IP addresses to access a single NFS volume. Client ID trunking is not supported.
vSphere Storage
154 VMware, Inc.