3.1.2 MxFS-Linux Administration Guide

Chapter 2: Configure Export Groups 9

options, it is indeterminate which options the NFS service will

assume. It is therefore recommended that any given filesystem subtree

be exported by at most one Export Group.

• Although an Export Group can specify that only certain nodes can

export its filesystems, the contents of the Export Group are available

via the /etc/exports file on every node in the cluster. This means that

users can access the exported filesystems from nodes where the

Export Group is not defined by connecting via the physical address of

the node. However, such access is not highly available because there is

no Virtual NFS Service associated with those connections. This is not a

security concern because the entire cluster should be considered as a

single security domain (for this and other reasons). The administrator

can track which nodes are exporting highly available NFS services by

watching the Export Group high-availability monitors that are active

on those nodes.

Mount PSFS Filesystems

Before configuring Export Groups, ensure that the filesystems to be

exported are on PSFS filesystems and are mounted on all the pertinent

nodes with the “persist” mount option.

The Cluster Coherent Record Locks mount option should not be disabled

on filesystems that will be exported. (Setting the command-line

localbrlocks mount option also disables cluster-coherent record locks.)

NFS lock acquisitions will not work on filesystems mounted with

cluster-coherent record locks disabled.

See “Configure PSFS Filesystems,” in the Matrix Server Administration

Guide for details about creating and mounting PSFS filesystems.