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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 06:03:02 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 06:03:02 +0000 |
commit | 4897093455a2bf08f3db3a1132cc2f6f5484d77c (patch) | |
tree | 9e6373544263f003139431fb4b08f9766e1ed530 /utils/exportfs/exportfs.man | |
parent | Initial commit. (diff) | |
download | nfs-utils-upstream.tar.xz nfs-utils-upstream.zip |
Adding upstream version 1:2.6.4.upstream/1%2.6.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'utils/exportfs/exportfs.man')
-rw-r--r-- | utils/exportfs/exportfs.man | 337 |
1 files changed, 337 insertions, 0 deletions
diff --git a/utils/exportfs/exportfs.man b/utils/exportfs/exportfs.man new file mode 100644 index 0000000..6d417a7 --- /dev/null +++ b/utils/exportfs/exportfs.man @@ -0,0 +1,337 @@ +.\"@(#)exportfs.8" +.\" +.\" Copyright (C) 1995 Olaf Kirch <okir@monad.swb.de> +.\" Modifications 1999-2003 Neil Brown <neilb@cse.unsw.edu.au> +.\" +.TH exportfs 8 "30 September 2013" +.SH NAME +exportfs \- maintain table of exported NFS file systems +.SH SYNOPSIS +.BI "/usr/sbin/exportfs [-avi] [-o " "options,.." "] [" "client:/path" " ..] +.br +.BI "/usr/sbin/exportfs -r [-v]" +.br +.BI "/usr/sbin/exportfs [-av] -u [" "client:/path" " ..] +.br +.BI "/usr/sbin/exportfs [-v] +.br +.BI "/usr/sbin/exportfs -f" +.br +.BI "/usr/sbin/exportfs -s" +.br +.SH DESCRIPTION +An NFS server maintains a table of local physical file systems +that are accessible to NFS clients. +Each file system in this table is referred to as an +.IR "exported file system" , +or +.IR export , +for short. +.PP +The +.B exportfs +command maintains the current table of exports for the NFS server. +The master export table is kept in a file named +.IR /var/lib/nfs/etab . +This file is read by +.B rpc.mountd +when a client sends an NFS MOUNT request. +.PP +Normally the master export table is initialized with the contents of +.I /etc/exports +and files under +.I /etc/exports.d +by invoking +.BR "exportfs -a" . +However, a system administrator can choose to add or delete +exports without modifying +.I /etc/exports +or files under +.I /etc/exports.d +by using the +.B exportfs +command. +.PP +.B exportfs +and its partner program +.B rpc.mountd +work in one of two modes: a legacy mode which applies to 2.4 and +earlier versions of the Linux kernel, and a new mode which applies to +2.6 and later versions, providing the +.B nfsd +virtual filesystem has been mounted at +.I /proc/fs/nfsd +or +.IR /proc/fs/nfs . +On 2.6 kernels, if this filesystem is not mounted, the legacy mode is used. +.PP +In the new mode, +.B exportfs +does not give any information to the kernel, but provides it only to +.B rpc.mountd +through the +.I /var/lib/nfs/etab +file. +.B rpc.mountd +then manages kernel requests for information about exports, as needed. +.PP +In the legacy mode, +exports which identify a specific host, rather than a subnet or netgroup, +are entered directly into the kernel's export table, +as well as being written to +.IR /var/lib/nfs/etab . +Further, exports listed in +.I /var/lib/nfs/rmtab +which match a non host-specific export request will cause an +appropriate export entry for the host given in +.I rmtab +to be added to the kernel's export table. +.SH OPTIONS +.TP +.B \-d kind " or " \-\-debug kind +Turn on debugging. Valid kinds are: all, auth, call, general and parse. +Debugging can also be turned on by setting +.B debug= +in the +.B [exportfs] +section of +.IR /etc/nfs.conf . + +.TP +.B -a +Export or unexport all directories. +.TP +.BI "-o " options,... +Specify a list of export options in the same manner as in +.BR exports (5). +.TP +.B -i +Ignore the +.I /etc/exports +file and files under +.I /etc/exports.d +directory. Only default options and options given on the command line are used. +.TP +.B -r +Reexport all directories, synchronizing +.I /var/lib/nfs/etab +with +.IR /etc/exports +and files under +.IR /etc/exports.d . +This option removes entries in +.I /var/lib/nfs/etab +which have been deleted from +.I /etc/exports +or files under +.IR /etc/exports.d , +and removes any entries from the +kernel export table which are no longer valid. +.TP +.B -u +Unexport one or more directories. +.TP +.B -f +If +.I /proc/fs/nfsd +or +.I /proc/fs/nfs +is mounted, flush everything out of the kernel's export table. +Fresh entries for active clients are added to the kernel's export table by +.B rpc.mountd +when they make their next NFS mount request. +.TP +.B -v +Be verbose. When exporting or unexporting, show what's going on. When +displaying the current export list, also display the list of export +options. +.TP +.B -s +Display the current export list suitable for /etc/exports. + +.SH CONFIGURATION FILE +The +.B [exportfs] +section of the +.I /etc/nfs.conf +configuration file can contain a +.B debug +value, which can be one or more from the list +.BR general , +.BR call , +.BR auth , +.BR parse , +.BR all . +When a list is given, the members should be comma-separated. + +.B exportfs +will also recognize the +.B state-directory-path +value from both the +.B [mountd] +section and the +.B [exportd] +section + +.SH DISCUSSION +.SS Exporting Directories +The first synopsis shows how to invoke +.B exportfs +when adding new entries to the export table. When using +.BR "exportfs -a" , +all exports listed in +.I /etc/exports +and files under +.I /etc/exports.d +are added to +.IR /var/lib/nfs/etab . +The kernel's export table is also updated as needed. +.PP +The +.I host:/path +argument specifies a local directory to export, +along with the client or clients who are permitted to access it. +See +.B exports(5) +for a description of supported options and access list formats. +.PP +IPv6 presentation addresses contain colons, which are already used +to separate the "host" and "path" command line arguments. +When specifying a client using a raw IPv6 address, +enclose the address in square brackets. +For IPv6 network addresses, place the prefix just after the closing +bracket. +.PP +To export a directory to the world, simply specify +.IR :/path . +.PP +The export options for a particular host/directory pair derive from +several sources. +The default export options are +.BR sync,ro,root_squash,wdelay . +These can be overridden by entries in +.IR /etc/exports +or files under +.IR /etc/exports.d . +.PP +A system administrator may override options from these sources using the +.B -o +command-line option on +.BR exportfs . +This option takes a comma-separated list of options in the same fashion +as one would specify them in +.IR /etc/exports . +In this way +.B exportfs +can be used to modify the export options of an already exported directory. +.SS Unexporting Directories +The third synopsis shows how to unexport a currently exported directory. +When using +.BR "exportfs -ua" , +all entries listed in +.I /var/lib/nfs/etab +are removed from the kernel export tables, and the file is cleared. This +effectively shuts down all NFS activity. +.PP +To remove an export, specify a +.I host:/path +pair. This deletes the specified entry from +.I /var/lib/nfs/etab +and removes the corresponding kernel entry (if any). +.PP +.SS Dumping the Export Table +Invoking +.B exportfs +without options shows the current list of exported file systems. +Adding the +.B -v +option causes +.B exportfs +to display the export options for each export. +.SH EXAMPLES +The following adds all directories listed in +.I /etc/exports +and files under +.I /etc/exports.d +to +.I /var/lib/nfs/etab +and pushes the resulting export entries into the kernel: +.PP +.nf +.B "# exportfs -a +.fi +.PP +To export the +.I /usr/tmp +directory to host +.BR django , +allowing insecure file locking requests from clients: +.PP +.nf +.B "# exportfs -o insecure_locks django:/usr/tmp +.fi +.PP +To unexport the +.I /usr/tmp +directory: +.PP +.nf +.B "# exportfs -u django:/usr/tmp +.fi +.PP +To unexport all exports listed in +.IR /etc/exports +and files under +.IR /etc/exports.d : +.PP +.nf +.B "# exportfs -au +.fi +.PP +To export the +.I /usr/tmp +directory to IPv6 link-local clients: +.PP +.nf +.B "# exportfs [fe80::]/64:/usr/tmp +.fi +.SH USAGE NOTES +Exporting to IP networks or DNS and NIS domains does not enable clients +from these groups to access NFS immediately. +Rather, these sorts of exports are hints to +.BR rpc.mountd (8) +to grant any mount requests from these clients. +This is usually not a problem, because any existing mounts are preserved in +.I rmtab +across reboots. +.PP +When unexporting a network or domain entry, any current exports to members +of this group will be checked against the remaining valid exports and +if they themselves are no longer valid they will be removed. +.SH FILES +.TP 2.5i +.I /etc/exports +input file listing exports, export options, and access control lists +.TP 2.5i +.I /etc/exports.d +directory where extra input files are stored. +.B Note: +only files that end with +.I .exports +are used. +.TP 2.5i +.I /var/lib/nfs/etab +master table of exports +.TP 2.5i +.I /var/lib/nfs/rmtab +table of clients accessing server's exports +.SH SEE ALSO +.BR exports (5), +.BR nfs.conf (5), +.BR rpc.mountd (8), +.BR exportd (8), +.BR netgroup (5) +.SH AUTHORS +Olaf Kirch <okir@monad.swb.de> +.br +Neil Brown <neilb@cse.unsw.edu.au> |