exportfs(1M)

NAME

exportfs — export and unexport directories to NFS clients

SYNOPSIS

/usr/sbin/exportfs [-auv]

/usr/sbin/exportfs [-uv] [dir ...]

/usr/sbin/exportfs -i [-o options] [-v] [dir ...]

DESCRIPTION

The exportfs command makes a local directory or file available to NFS clients for mounting over the network. Directories and files cannot be NFS-mounted unless they are first exported by exportfs.

exportfs is normally invoked at boot time by the /sbin/init.d/nfs.server script, and uses information contained in the /etc/exports file to export the file or file system named by each dir, which must be specified as a full path name.

If no options or arguments are specified in the command line, exportfs displays a list of the currently exported directories and files on standard output.

A superuser can run exportfs at any time to alter the list or characteristics of exported directories and files.

Options

exportfs recognizes the following options:

-a

Export all directories listed in /etc/exports. If -u is also specified, unexport all of the currently exported directories.

-i

Ignore the options in /etc/exports. Normally, exportfs consults /etc/exports for the options associated with the exported directory.

-u

Unexport the indicated directories.

-v

Verbose. Print each directory or file name as it is exported or unexported.

-o options

Specify a comma-separated list of optional characteristics for the directory being exported. The list of options can include any of the following:

async

All NFS Protocol Version 2 mounts will be asynchronous. This option is ignored for NFS PV3. Refer to exports(4) for warnings when using this option.

ro

Export the directory read-only. If not specified, the directory is exported read-write.

rw=hostname[:hostname]...

Export the directory read/write only to the listed clients. No other systems can access the directory. Up to 256 hostnames can be specified.

anon=uid

If a request comes from an unknown user, use uid as the effective user ID.

Root users (user ID 0) are always treated as user unknown by the NFS server unless they are included in the root option below.

If the client is a UNIX system, only root users are considered unknown. All other users are recognized even if they are not in /etc/passwd.

The default value for uid is the user ID of user nobody. If user nobody does not exist, the value -2 is used. Setting the value of anon to -1 disables anonymous access.

root=hostname[:hostname]...

Give root access only to the root users from a specified hostname. The default is for no hosts to be granted root access. Up to 256 hostnames can be specified.

access=client[:client]...

Give mount access to each client listed. A client can either be a host name, or a netgroup (see netgroup(4)). exportfs checks for each client in the list first in file /etc/hosts, then in /etc/netgroup. The default value allows any machine to mount the given directory.

DIAGNOSTICS

If an NFS-mounted directory is unexported by exportfs, any access by the client to the directory causes an NFS stale file handle error. However, if exportfs is used to remove a client from the access list of an exported directory, an NFS stale file handle error does not result from any access by the client to the directory.

EXAMPLES

The following invocation of exportfs lists currently exported directories and files:

exportfs 

Export entries in /etc/exports

exportfs -a 

Unexport all exported files and directories:

exportfs -ua 

Unexport all exported files and directories and print each directory or file name as it is unexported:

exportfs -uav 

Export /usr to the world, ignoring options in /etc/exports:

exportfs -i /usr 

Export /usr/bin and /var/adm read-only to the world:

exportfs -i -o ro /usr/bin /var/adm 

Export /usr/bin read-write only to systems polk and vanness:

exportfs -i -o rw=polk:vanness /usr/bin 

Export root access on /var/adm only to the system named pine, and mount access to both pine and geary:

exportfs -i -o root=pine,access=pine:geary /var/adm 

WARNINGS

You cannot export a directory that resides within the same file system and is either a parent or sub-directory of a directory that is currently exported. For example, /usr and /usr/local cannot both be exported if they reside in the same disk partition.

If you unexport a directory, remove a client from the access list, then export again, the client still has access to the directory until the client unmounts the directory. Removing a client from the root or rw list takes effect immediately.

/etc/xtab is a system file that contains a list of currently exported directories and files. This file is maintained by exportfs. To ensure that this file is always synchronous with current system data structures, do not attempt to edit /etc/xtab by hand.

FILES

/etc/exports: Static export information
/etc/netgroup: List of network groups
/etc/xtab: Current state of exported directories

exportfs(1M)

Technical documentation

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