6.5.1

Table Of Contents
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NFS Security
With NFS 3 and NFS 4.1, ESXi supports the AUTH_SYS security. In addition, for NFS 4.1, the
Kerberos security mechanism is supported.
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NFS Multipathing
While NFS 3 with ESXi does not provide multipathing support, NFS 4.1 supports multiple paths.
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NFS and Hardware Acceleration
Virtual disks created on NFS datastores are thin-provisioned by default. To be able to create thick-
provisioned virtual disks, you must use hardware acceleration that supports the Reserve Space
operation.
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NFS Datastores
When you create an NFS datastore, make sure to follow specific guidelines.
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.
The guidelines include the following items.
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Make sure that the NAS servers you use are listed in the VMware HCL. Use the correct version for
the server firmware.
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Ensure that the NFS volume is exported using NFS over TCP.
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Make sure that the NAS server exports a particular share as either NFS 3 or NFS 4.1. The NAS
server must not provide both protocol versions for the same share. The NAS server must enforce this
policy because ESXi does not prevent mounting the same share through different NFS versions.
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NFS 3 and non-Kerberos (AUTH_SYS) 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 the NAS servers use the no_root_squash option.
If the NAS server does not grant root access, you can still mount the NFS datastore on the host.
However, you cannot create any virtual machines on the datastore.
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If the underlying NFS volume is read-only, make sure that the volume is exported as a read-only
share by the NFS server. Or mount the volume as a read-only datastore on the ESXi host. Otherwise,
the host considers the datastore to be read-write and might not open the files.
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.
For more information, see the vSphere Networking documentation.
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For network connectivity, use a standard network adapter in your ESXi host.
vSphere Storage
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