Red Hat ENTERPRISE LINUX 3 Reference Manual page 136

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Each default for every exported file system must be explicitly overridden. For example, if the
option is not specified, then the exported file system is shared as read-only. The following is a sample
line from
/etc/exports
/another/exported/directory 192.168.0.3(rw,sync)
In this example
192.168.0.3
transfers to disk are committed to the disk before the write request by the client is completed.
Additionally, other options are available where no default value is specified. These include the ability
to disable sub-tree checking, allow access from insecure ports, and allow insecure file locks (necessary
for certain early NFS client implementations). Refer to the
lesser used options.
Warning
The format of the
acter. Remember to always separate exported file systems from hosts and hosts from one another
with a space character. However, there should be no other space characters in the file except on
comment lines.
For example, the following two lines do not mean the same thing:
/home bob.example.com(rw)
/home bob.example.com (rw)
The first line allows only users from
second line allows users from
the rest of the world can mount it read/write.
For detailed instructions on configuring an NFS server by editing
titled Network File System (NFS) in the Red Hat Enterprise Linux System Administration Guide.
9.3.2. The
exportfs
Every file system being exported to remote users via NFS, as well as the access level for those file sys-
tems, are listed in the
command launches and reads this file, and passes to
available to remote users.
When issued manually, the
port or unexport directories without restarting the NFS service. When passed the proper options, the
/usr/sbin/exportfs
refers to the
rpc.mountd
list of exported file systems take effect immediately.
The following is a list of commonly used options available for
— Causes all directories listed in
• -r
list in
/etc/lib/nfs/xtab
have been made to
— Causes all directories to be exported or unexported, depending on what other options are
• -a
passed to
/usr/sbin/exportfs
ports all file systems specified in
which overrides two default options:
can mount
file is very precise, particularly in regards to use of the space char-
/etc/exports
bob.example.com
bob.example.com
Command
file. When the
/etc/exports
/usr/sbin/exportfs
command writes the exported file systems to
file when deciding access privileges to a file system, changes to the
xtab
/etc/exports
. This option effectively refreshes the export list with any changes that
.
/etc/exports
. If no other options are specified,
/etc/exports
Chapter 9. Network File System (NFS)
/another/exported/directory/
exports
read/write access to the
to mount the directory read-only (the default), but
/etc/exports
service starts, the
nfs
rpc.mountd
command allows the root user to selectively ex-
/usr/sbin/exportfs
to be exported by constructing a new export
.
read/write and all
man page for details on these
directory. The
/home
, refer to the chapter
/usr/sbin/exportfs
and the file systems
rpc.nfsd
/var/lib/nfs/xtab
:
/usr/sbin/exportfs
rw
. Since
ex-