1.\" $OpenBSD: swapon.8,v 1.10 1999/06/04 02:45:24 aaron Exp $ 2.\" $NetBSD: swapon.8,v 1.8 1995/08/18 14:51:35 pk Exp $ 3.\" 4.\" Copyright (c) 1980, 1991, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. All advertising materials mentioning features or use of this software 16.\" must display the following acknowledgement: 17.\" This product includes software developed by the University of 18.\" California, Berkeley and its contributors. 19.\" 4. Neither the name of the University nor the names of its contributors 20.\" may be used to endorse or promote products derived from this software 21.\" without specific prior written permission. 22.\" 23.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS `AS IS'' AND 24.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33.\" SUCH DAMAGE. 34.\" 35.\" @(#)swapon.8 8.1 (Berkeley) 6/5/93 36.\" 37.Dd June 5, 1993 38.Dt SWAPON 8 39.Os 40.Sh NAME 41.Nm swapon 42.Nd "specify additional device for paging and swapping" 43.Sh SYNOPSIS 44.Nm swapon 45.Fl a 46.Nm swapon 47.Ar special_file ... 48.Sh DESCRIPTION 49.Nm 50is used to specify additional devices on which paging and swapping 51are to take place. 52The system begins by swapping and paging on only a single device 53so that only one disk is required at bootstrap time. 54Calls to 55.Nm 56normally occur in the system multi-user initialization file 57.Pa /etc/rc 58making all swap devices available, so that the paging and swapping 59activity is interleaved across several devices. 60.Pp 61Normally, the first form is used: 62.Bl -tag -width Ds 63.It Fl a 64All devices marked as 65.Dq sw 66swap devices in 67.Pa /etc/fstab 68are made available. 69.El 70.Pp 71The second form gives individual block devices as given 72in the system swap configuration table. The call makes only this space 73available to the system for swap allocation. 74.Sh FILES 75.Bl -tag -width /dev/[ru][pk]?b -compact 76.It Pa /dev/[ru][pk]?b 77standard paging devices 78.It Pa /etc/fstab 79ASCII filesystem description table 80.El 81.Sh SEE ALSO 82.Xr swapon 2 , 83.Xr fstab 5 , 84.Xr init 8 , 85.Xr rc 8 , 86.Xr vnconfig 8 87.Sh BUGS 88There is no way to stop paging and swapping on a device. 89It is therefore not possible to make use of devices which may be 90dismounted during system operation. 91.Sh HISTORY 92The 93.Nm 94command appeared in 95.Bx 4.0 . 96