-.TH EXPORTS 5 "28 October 1999"
-.UC 5
+.TH EXPORTS 5 "4 March 2005" "Linux" "Linux File Formats Manual"
.SH NAME
exports \- NFS file systems being exported (for Kernel based NFS)
.SH SYNOPSIS
understands the following export options:
.TP
.IR secure "\*d
-This option requires that requests originate on an internet port less
+This option requires that requests originate on an Internet port less
than IPPORT_RESERVED (1024). This option is on by default. To turn it
off, specify
.IR insecure .
an unclean server restart (i.e. a crash) can cause data to be lost or
corrupted.
-In releases of nfs-utils upto and including 1.0.0, this option was the
-default. In this and future releases,
+.TP
+.IR sync
+Reply to requests only after the changes have been committed to stable
+storage (see
+.IR async
+above).
+
+In releases of nfs-utils up to and including 1.0.0, this option was the
+default. In all subsequence releases,
.I sync
is the default, and
.I async
must be explicit requested if needed.
-To help make system adminstrators aware of this change, 'exportfs'
+To help make system administrators aware of this change, 'exportfs'
will issue a warning if neither
.I sync
nor
The option can be explicitly disabled with
.IR hide .
.TP
+.IR crossmnt
+This option is similar to
+.I nohide
+but it makes it possible for clients to move from the filesystem marked
+with crossmnt to exported filesystems mounted on it. Thus when a child
+filesystem "B" is mounted on a parent "A", setting crossmnt on "A" has
+the same effect as setting "nohide" on B.
+.TP
.IR no_subtree_check
This option disables subtree checking, which has mild security
-implications, but can improve reliability is some circumstances.
+implications, but can improve reliability in some circumstances.
If a subdirectory of a filesystem is exported, but the whole
filesystem isn't then whenever a NFS request arrives, the server must
directories to which only root has access can only be accessed if the
filesystem is exported with
.I no_root_squash
-(see below), even the file itself allows more general access.
+(see below), even if the file itself allows more general access.
As a general guide, a home directory filesystem, which is normally
exported at the root and may see lots of file renames, should be
requested with
.IR subtree_check .
+From release 1.1.0 of nfs-utils onwards, the default will be
+.I no_subtree_check
+as subtree_checking tends to cause more problems than it is worth.
+If you genuinely require subtree checking, you should explicitly put
+that option in the
+.B exports
+file. If you put neither option,
+.I exportfs
+will warn you that the change is pending.
+
.TP
.IR insecure_locks
.TP
.IR auth_nlm ,
or
.IR secure_locks .
+.TP
+.IR no_acl
+On some specially patched kernels, and when exporting filesystems that
+support ACLs, this option tells nfsd not to reveal ACLs to clients, so
+they will see only a subset of actual permissions on the given file
+system. This option is safe for filesystems used by NFSv2 clients and
+old NFSv3 clients that perform access decisions locally. Current
+NFSv3 clients use the ACCESS RPC to perform all access decisions on
+the server. Note that the
+.I no_acl
+option only has effect on kernels specially patched to support it, and
+when exporting filesystems with ACL support. The default is to export
+with ACL support (i.e. by default,
+.I no_acl
+is off).
'''.TP
'''.I noaccess
If a path is given (e.g.
.IR mountpoint= "/path or " mp= /path)
-then the nominted path must be a mountpoint for the exportpoint to be
+then the nominated path must be a mountpoint for the exportpoint to be
exported.
.TP
'''in the password file at startup time. If it isn't found, a uid and gid
.I exportfs
chooses a uid and gid
-of -2 (i.e. 65534) for squashed access. These values can also be overridden by
+of 65534 for squashed access. These values can also be overridden by
the
.IR anonuid " and " anongid
options.
.TP
.IR root_squash
Map requests from uid/gid 0 to the anonymous uid/gid. Note that this does
-not apply to any other uids that might be equally sensitive, such as user
-.IR bin .
+not apply to any other uids or gids that might be equally sensitive, such as
+user
+.IR bin
+or group
+.IR staff .
.TP
.IR no_root_squash
Turn off root squashing. This option is mainly useful for diskless clients.
'''entry.
.SH FILES
/etc/exports
+.SH SEE ALSO
+.BR exportfs (8),
+.BR netgroup (5),
+.BR mountd (8),
+.BR nfsd (8),
+.BR showmount (8).
'''.SH 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