[thirdparty/util-linux.git] / mount / swapon.8

.\" Copyright (c) 1980, 1991 Regents of the University of California.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)swapon.8	6.3 (Berkeley) 3/16/91
.\"
.\" Sun Dec 27 12:31:30 1992: Modified by faith@cs.unc.edu
.\" Sat Mar  6 20:46:02 1993: Modified by faith@cs.unc.edu
.\" Sat Oct  9 09:35:30 1993: Converted to man format by faith@cs.unc.edu
.\" Sat Nov 27 20:22:42 1993: Updated authorship information, faith@cs.unc.edu
.\" Mon Sep 25 14:12:38 1995: Added -v and -p information
.\" Tue Apr 30 03:32:07 1996: Added some text from A. Koppenhoefer
.\"
.TH SWAPON 8 "25 September 1995" "Linux 1.x" "Linux Programmer's Manual"
.SH NAME
swapon, swapoff \- enable/disable devices and files for paging and swapping
.SH SYNOPSIS
.B /sbin/swapon [\-h \-V]
.br
.B /sbin/swapon \-a [\-v]
.br
.BI "/sbin/swapon [\-v] [\-p " "priority" "] " " specialfile " ...
.br
.B /sbin/swapon [\-s]
.br
.B /sbin/swapoff [\-h \-V]
.br
.B /sbin/swapoff \-a
.br
.BI /sbin/swapoff " specialfile " ...
.SH DESCRIPTION
.B Swapon
is used to specify devices on which paging and swapping are to take place.
Calls to
.B swapon
normally occur in the system multi-user initialization file
.I /etc/rc
making all swap devices available, so that the paging and swapping activity
is interleaved across several devices and files.

Normally, the first form is used:
.TP
.B \-h
Provide help
.TP
.B \-V
Display version
.TP
.B \-s
Display swap usage summary by device. Equivalent to "cat /proc/swaps".
Not available before Linux 2.1.25.
.TP
.B \-a
All devices marked as ``sw'' swap devices in
.I /etc/fstab
are made available.
.TP
.BI \-p " priority"
Specify priority for
.BR swapon .
This option is only available if
.B swapon
was compiled under and is used under a 1.3.2 or later kernel.
.I priority
is a value between 0 and 32767. See
.BR swapon (2)
for a full description of swap priorities. Add
.BI pri= value
to the option field of
.I /etc/fstab
for use with
.BR "swapon -a" .
.PP
.B Swapoff
disables swapping on the specified devices and files.
When the
.B \-a
flag is given, swapping is disabled on all known swap devices and files
(as found in
.I /proc/swaps
or
.IR /etc/fstab ).
.SH NOTE
You should not use
.B swapon
on a file with holes.
Swap over NFS may not work.
.SH SEE ALSO
.BR swapon (2),
.BR swapoff (2),
.BR fstab (5),
.BR init (8),
.BR mkswap (8),
.BR rc (8),
.BR mount (8)
.SH FILES
.I /dev/hd??
standard paging devices
.br
.I /dev/sd??
standard (SCSI) paging devices
.br
.I /etc/fstab
ascii filesystem description table
.SH HISTORY
The
.B swapon
command appeared in 4.0BSD.
Commit	Line	Data
6dbe3af9 KZ	1	.\" Copyright (c) 1980, 1991 Regents of the University of California.
	2	.\" All rights reserved.
	3	.\"
	4	.\" Redistribution and use in source and binary forms, with or without
	5	.\" modification, are permitted provided that the following conditions
	6	.\" are met:
	7	.\" 1. Redistributions of source code must retain the above copyright
	8	.\" notice, this list of conditions and the following disclaimer.
	9	.\" 2. Redistributions in binary form must reproduce the above copyright
	10	.\" notice, this list of conditions and the following disclaimer in the
	11	.\" documentation and/or other materials provided with the distribution.
	12	.\" 3. All advertising materials mentioning features or use of this software
	13	.\" must display the following acknowledgement:
	14	.\" This product includes software developed by the University of
	15	.\" California, Berkeley and its contributors.
	16	.\" 4. Neither the name of the University nor the names of its contributors
	17	.\" may be used to endorse or promote products derived from this software
	18	.\" without specific prior written permission.
	19	.\"
	20	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	21	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	22	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	23	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	24	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	25	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	26	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	27	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	28	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	29	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	30	.\" SUCH DAMAGE.
	31	.\"
	32	.\" @(#)swapon.8 6.3 (Berkeley) 3/16/91
	33	.\"
	34	.\" Sun Dec 27 12:31:30 1992: Modified by faith@cs.unc.edu
	35	.\" Sat Mar 6 20:46:02 1993: Modified by faith@cs.unc.edu
	36	.\" Sat Oct 9 09:35:30 1993: Converted to man format by faith@cs.unc.edu
	37	.\" Sat Nov 27 20:22:42 1993: Updated authorship information, faith@cs.unc.edu
726f69e2	38	.\" Mon Sep 25 14:12:38 1995: Added -v and -p information
fd6b7a7f	39	.\" Tue Apr 30 03:32:07 1996: Added some text from A. Koppenhoefer
6dbe3af9	40	.\"
726f69e2	41	.TH SWAPON 8 "25 September 1995" "Linux 1.x" "Linux Programmer's Manual"
6dbe3af9 KZ	42	.SH NAME
	43	swapon, swapoff \- enable/disable devices and files for paging and swapping
	44	.SH SYNOPSIS
726f69e2	45	.B /sbin/swapon [\-h \-V]
6dbe3af9	46	.br
726f69e2	47	.B /sbin/swapon \-a [\-v]
6dbe3af9	48	.br
726f69e2	49	.BI "/sbin/swapon [\-v] [\-p " "priority" "] " " specialfile " ...
6dbe3af9	50	.br
fd6b7a7f KZ	51	.B /sbin/swapon [\-s]
fd6b7a7f KZ	52	.br
726f69e2 KZ	53	.B /sbin/swapoff [\-h \-V]
	54	.br
	55	.B /sbin/swapoff \-a
	56	.br
	57	.BI /sbin/swapoff " specialfile " ...
6dbe3af9 KZ	58	.SH DESCRIPTION
	59	.B Swapon
	60	is used to specify devices on which paging and swapping are to take place.
	61	Calls to
	62	.B swapon
	63	normally occur in the system multi-user initialization file
	64	.I /etc/rc
	65	making all swap devices available, so that the paging and swapping activity
	66	is interleaved across several devices and files.
	67
	68	Normally, the first form is used:
	69	.TP
726f69e2 KZ	70	.B \-h
	71	Provide help
	72	.TP
	73	.B \-V
	74	Display version
	75	.TP
fd6b7a7f	76	.B \-s
63cccae4 KZ	77	Display swap usage summary by device. Equivalent to "cat /proc/swaps".
63cccae4 KZ	78	Not available before Linux 2.1.25.
fd6b7a7f	79	.TP
6dbe3af9 KZ	80	.B \-a
	81	All devices marked as ``sw'' swap devices in
	82	.I /etc/fstab
	83	are made available.
726f69e2 KZ	84	.TP
	85	.BI \-p " priority"
	86	Specify priority for
	87	.BR swapon .
	88	This option is only available if
	89	.B swapon
	90	was compiled under and is used under a 1.3.2 or later kernel.
fd6b7a7f KZ	91	.I priority
	92	is a value between 0 and 32767. See
	93	.BR swapon (2)
	94	for a full description of swap priorities. Add
	95	.BI pri= value
	96	to the option field of
	97	.I /etc/fstab
	98	for use with
	99	.BR "swapon -a" .
6dbe3af9 KZ	100	.PP
6dbe3af9 KZ	101	.B Swapoff
63cccae4 KZ	102	disables swapping on the specified devices and files.
63cccae4 KZ	103	When the
6dbe3af9	104	.B \-a
63cccae4 KZ	105	flag is given, swapping is disabled on all known swap devices and files
	106	(as found in
	107	.I /proc/swaps
	108	or
	109	.IR /etc/fstab ).
5c36a0eb KZ	110	.SH NOTE
	111	You should not use
	112	.B swapon
	113	on a file with holes.
22853e4a	114	Swap over NFS may not work.
6dbe3af9	115	.SH SEE ALSO
22853e4a KZ	116	.BR swapon (2),
	117	.BR swapoff (2),
	118	.BR fstab (5),
	119	.BR init (8),
	120	.BR mkswap (8),
	121	.BR rc (8),
	122	.BR mount (8)
6dbe3af9	123	.SH FILES
726f69e2	124	.I /dev/hd??
6dbe3af9 KZ	125	standard paging devices
6dbe3af9 KZ	126	.br
726f69e2	127	.I /dev/sd??
6dbe3af9 KZ	128	standard (SCSI) paging devices
	129	.br
	130	.I /etc/fstab
	131	ascii filesystem description table
	132	.SH HISTORY
	133	The
	134	.B swapon
	135	command appeared in 4.0BSD.