Red Hat CLUSTER MANAGER - INSTALLATION AND Administration Manual page 105

Section 6.1:Setting Up an NFS Service
– Mount options — The mount information also designates the mount options. Note: by default,
the Linux NFS server does not guarantee that all write operations are synchronously written to
disk. In order to ensure synchronous writes, specify the sync mount option. Specifying the
sync mount option favors data integrity at the expense of performance. Refer to mount(8)
for detailed descriptions of the mount related parameters.
– Forced unmount — As part of the mount information, there will be a prompt as to whether
forced unmount should be enabled or not. When forced unmount is enabled, if any applications
running on the cluster server have the designated filesystem mounted when the service is being
disabled or relocated, then that application will be killed to allow the unmount to proceed.
• Export Information — for non-clustered NFS services, export information is typically placed in
/etc/exports. In contrast, clustered NFS services should not place export information in
/etc/exports; rather there will be a prompt for this information during service configuration.
Export information includes:
– Export directory — the export directory can be the same as the mount point specified with
the mount information. In this case, the entire filesystem is accessible through NFS. Alterna-
tively, a specified portion (subdirectory) of a mounted filesystem can be mounted instead of
the entire filesystem. By exporting subdirectories of a mountpoint, different access rights can
be allocated to different sets of NFS clients.
– Export client names — this parameter defines which systems will be allowed to access the file
system as NFS clients. Under this method, individual systems can be designated (e.g. fred), as
well as wildcards to allow groups of systems (e.g. *.wizzbang.com). Entering a client name
of * allows any client to mount the filesystem.
– Export client options — this parameter defines the access rights afforded to the corresponding
client(s). Examples include
otherwise, the default export options are ro,async,wdelay,root_squash.
Refer to exports(5) for detailed descriptions of the export parameter syntax.
When running the cluadmin utility to configure NFS services:
• Take extra care to correctly enter the service parameters. The validation logic associated with NFS
parameters is currently insufficient.
• In response to most of the prompts, you can enter the
6.1.3 Example NFS Service Configuration
In order to illustrate the configuration process for an NFS service, an example configuration is de-
scribed in this section. This example consists of setting up a single NFS export which houses the
home directories of 4 members of an accounting department. NFS client access will be restricted to
these four user's systems.
(read only), and
ro rw
[?]
(read write). Unless explicitly specified
character to obtain descriptive help text.
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