System information

Causes all directories listed in /etc/expo rts to be exported by constructing a new export
list in /etc/l ib/nfs/etab. This option effectively refreshes the export list with any
changes made to /etc/expo rts.
- a
Causes all directories to be exported or unexported, depending on what other options are
passed to /usr/sbi n/expo rtfs. If no other options are specified,
/usr/sbi n/expo rtfs exports all file systems specified in /etc/expo rts.
- o file-systems
Specifies directories to be exported that are not listed in /etc/expo rts. Replace file-
systems with additional file systems to be exported. These file systems must be formatted in
the same way they are specified in /etc/expo rts. This option is often used to test an
exported file system before adding it permanently to the list of file systems to be exported.
Refer to Section 9.7.1, “ The /etc/expo rts Configuration File” for more information on
/etc/expo rts syntax.
- i
Ignores /etc/expo rts; only options given from the command line are used to define
exported file systems.
- u
Unexports all shared directories. The command /usr/sbi n/expo rtfs -ua suspends
NFS file sharing while keeping all NFS daemons up. To re-enable NFS sharing, use
expo rtfs -r.
- v
Verbose operation, where the file systems being exported or unexported are displayed in
greater detail when the expo rtfs command is executed.
If no options are passed to the expo rtfs command, it displays a list of currently exported file
systems. For more information about the expo rtfs command, refer to man expo rtfs.
9.7 .2 .1 . Using expo rtfs wit h NFSv4
In Red Hat Enterprise Linux 6, no extra steps are required to configure NFSv4 exports as any
filesystems mentioned are automatically available to NFSv2, NFSv3, and NFSv4 clients using the
same path. This was not the case in previous versions.
To prevent clients from using NFSv4, turn it off by sellecting R PC NFSD AR G S= -N 4 in
/etc/sysco nfi g /nfs.
9.7.3. Running NFS Behind a Firewall
NFS requires rpcbi nd , which dynamically assigns ports for RPC services and can cause problems
for configuring firewall rules. To allow clients to access NFS shares behind a firewall, edit the
/etc/sysco nfi g /nfs configuration file to control which ports the required RPC services run on.
The /etc/sysco nfi g /nfs may not exist by default on all systems. If it does not exist, create it and
add the following variables, replacing port with an unused port number (alternatively, if the file exists,
un-comment and change the default entries as required):
MO UNT D _P O R T = port
Controls which TCP and UD P port mo untd (rpc. mo untd ) uses.
Red Hat Ent erprise Lin ux 6 St orage Admin ist rat io n G uide
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