EXPORTS(5)

NAME
exports - NFS file systems being exported

SYNOPSIS
/etc/exports

DESCRIPTION
The file /etc/exports serves as the access control list for file systems which may be exported to NFS clients. It it used by both the NFS mount daemon, mountd(8) and the NFS file server daemon nfsd(8).

The file format is similar to the SunOS exports file, except that netgroup names are not permitted, and several additional options are permitted. Each line contains a mount point and a list of machine names allowed to mount the file system at that point. An optional parenthesized list of mount parameters may follow each machine name. Blank lines are ignored, and a # introduces a comment to the end of the line.

These are the parameters that are currently recognized.

insecure
    Permit non-authenticated access from this machine.

unix-rpc *
    Require UNIX-domain RPC authentication from this machine. This simply requires that requests originate on an internet port IPPORT_RESERVED.

secure-rpc +
    Require secure RPC authentication from this machine. See the Sun documentation on Secure RPC.

kerberos +
    Require Kerberos authentication on accesses from this machine. See the MIT documentation on the Kerberos third-party authentication system.

root_squash
    Map requests from uid 0 on the client to uid NOBODY_UID (a compile-time option) on the server.

no_root_squash *
    Don't map requests from uid 0.

ro *
    Mount file hierarchy read-only.

rw  Mount file hierarchy read-write.

link_relative *
    Convert absolute symbolic links (where the link contents start with a slash) into relative links by prepending the necessary number of ../'s to get from the directory containing the link to the root on the server. This has subtle, perhaps questionable, semantics when the file hierarchy is not mounted at its root.

link_absolute
    Leave all symbolic link as they are (the normal behavior for Sun-supplied NFS servers).

map_identity *
    Assume the client and server share the same uid/gid space.

map_daemon
    Map local and remote names and numeric ids using a lname/uid map daemon on the client from which the NFS request originated, to map between the client and server uid spaces (see ugidd(8)). This only works if nfsd(8) is compiled with Mark Shand's ugidd code.

( * indicates defaults) ( + indicates not implemented)

EXAMPLE

# sample /etc/exports file
/	master(rw) trusty(rw)
/projects	proj*.local.domain(rw)
/usr	*.local.domain(ro)
/pub	(ro,insecure,root_quash)

FILES
/etc/exports

DIAGNOSTICS
An error parsing the file is reported using syslogd(8) as level NOTICE from a DAEMON whenever nfsd(8) or mountd(8) is started up. Any unknown host is reported at that time, but often not all hosts are not yet known to named(8) at boot time, thus as hosts are found they are reported with the same syslogd(8) parameters.

SEE ALSO
mountd(8), nfsd(8)