ESXi supports NFS protocols version 3 and 4.1. To support both versions, ESXi uses two different NFS clients.

Comparing Versions of NFS Clients

The following table lists capabilities that the NFS version 3 and 4.1 support.

Characteristics

NFS version 3

NFS version 4.1

Security mechanisms

AUTH_SYS

AUTH_SYS and Kerberos (krb5 and krb5i)

Encryption algorithms with Kerberos

N/A

AES256-CTS-HMAC-SHA1-96 and AES128-CTS-HMAC-SHA1-96

Multipathing

Not supported

Supported through the session trunking

Locking mechanisms

Propriety client-side locking

Server-side locking

Hardware acceleration

Supported

Supported

Thick virtual disks

Supported

Supported

IPv6

Supported

Supported for AUTH_SYS and Kerberos

ISO images presented as CD-ROMs to virtual machines

Supported

Supported

Virtual machine snapshots

Supported

Supported

Virtual machines with virtual disks greater than 2 TB

Supported

Supported

NFS Protocols and vSphere Solutions

The following table lists major vSphere solutions that NFS versions support.

vSphere Features

NFS version 3

NFS version 4.1

vMotion and Storage vMotion

Yes

Yes

High Availability (HA)

Yes

Yes

Fault Tolerance (FT)

Yes

Yes

Distributed Resource Scheduler (DRS)

Yes

Yes

Host Profiles

Yes

Yes

Storage DRS

Yes

No

Storage I/O Control

Yes

No

Site Recovery Manager

Yes

No

Virtual Volumes

Yes

Yes

vSphere Replication

Yes

Yes

vRealize Operations Manager

Yes

Yes

NFS 4.1 and Fault Tolerance

Virtual machines on NFS v4.1 support the new Fault Tolerance mechanism introduced in vSphere 6.0.

Virtual machines on NFS v4.1 do not support the old, legacy Fault Tolerance mechanism.

In vSphere 6.0, the newer Fault Tolerance mechanism can accommodate symmetric multiprocessor (SMP) virtual machines with up to four vCPUs. Earlier versions of vSphere used a different technology for Fault Tolerance, with different requirements and characteristics.

NFS Upgrades

When you upgrade ESXi to version 6.5, existing NFS 4.1 datastores automatically begin supporting functionalities that were not available in the previous ESXi release. These functionalities include Virtual Volumes, hardware acceleration, and so on.

ESXi does not support automatic datastore conversions from NFS version 3 to NFS 4.1.

If you want to upgrade your NFS 3 datastore, the following options are available:

  • Create the NFS 4.1 datastore, and then use Storage vMotion to migrate virtual machines from the old datastore to the new one.

  • Use conversion methods provided by your NFS storage server. For more information, contact your storage vendor.

  • Unmount the NFS 3 datastore, and then mount as NFS 4.1 datastore.

    Caution:

    If you use this option, make sure to unmount the datastore from all hosts that have access to the datastore. The datastore can never be mounted by using both protocols at the same time.