6.5.1

Table Of Contents
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:
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Create the NFS 4.1 datastore, and then use Storage vMotion to migrate virtual machines from the old
datastore to the new one.
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Use conversion methods provided by your NFS storage server. For more information, contact your
storage vendor.
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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.
NFS Storage Guidelines and Requirements
When you use NFS storage, follow specific guidelines related to NFS server configuration, networking,
NFS datastores, and so on.
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NFS Server Configuration
When you configure NFS servers to work with ESXi, follow recommendation of your storage vendor.
In addition to these general recommendations, use specific guidelines that apply to NFS in vSphere
environment.
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NFS Networking
An ESXi host uses TCP/IP network connection to access a remote NAS server. Certain guidelines
and best practices exist for configuring the networking when you use NFS storage.
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NFS File Locking
File locking mechanisms are used to restrict access to data stored on a server to only one user or
process at a time. NFS 3 and NFS 4.1 use incompatible file locking mechanisms.
vSphere Storage
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