1.\" Copyright (c) 1980, 1991, 1993 2.\" The Regents of the University of California. 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.2 8.1 (Berkeley) 6/4/93 33.\" $FreeBSD: src/lib/libc/sys/swapon.2,v 1.6.2.6 2001/12/14 18:34:01 ru Exp $ 34.\" $DragonFly: src/lib/libc/sys/swapon.2,v 1.3 2006/02/17 19:35:06 swildner Exp $ 35.\" 36.Dd June 4, 1993 37.Dt SWAPON 2 38.Os 39.Sh NAME 40.Nm swapon 41.Nd add a swap device for interleaved paging/swapping 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.In unistd.h 46.Ft int 47.Fn swapon "const char *special" 48.Sh DESCRIPTION 49.Fn Swapon 50makes the block device 51.Fa special 52available to the system for 53allocation for paging and swapping. The names of potentially 54available devices are known to the system and defined at system 55configuration time. The size of the swap area on 56.Fa special 57is calculated at the time the device is first made available 58for swapping. 59.Sh RETURN VALUES 60If an error has occurred, a value of -1 is returned and 61.Va errno 62is set to indicate the error. 63.Sh ERRORS 64.Fn Swapon 65succeeds unless: 66.Bl -tag -width Er 67.It Bq Er ENOTDIR 68A component of the path prefix is not a directory. 69.It Bq Er ENAMETOOLONG 70A component of a pathname exceeded 255 characters, 71or an entire path name exceeded 1023 characters. 72.It Bq Er ENOENT 73The named device does not exist. 74.It Bq Er EACCES 75Search permission is denied for a component of the path prefix. 76.It Bq Er ELOOP 77Too many symbolic links were encountered in translating the pathname. 78.It Bq Er EPERM 79The caller is not the super-user. 80.It Bq Er ENOTBLK 81.Fa Special 82is not a block device. 83.It Bq Er EBUSY 84The device specified by 85.Fa special 86has already 87been made available for swapping 88.It Bq Er EINVAL 89The device configured by 90.Fa special 91was not 92configured into the system as a swap device. 93.It Bq Er ENXIO 94The major device number of 95.Fa special 96is out of range (this indicates no device driver exists 97for the associated hardware). 98.It Bq Er EIO 99An I/O error occurred while opening the swap device. 100.It Bq Er EFAULT 101.Fa Special 102points outside the process's allocated address space. 103.El 104.Sh SEE ALSO 105.Xr config 8 , 106.Xr swapon 8 107.Sh HISTORY 108The 109.Fn swapon 110function call appeared in 111.Bx 4.0 . 112.Sh BUGS 113There is no way to stop swapping on a disk so that the pack may be 114dismounted. 115.Pp 116This call will be upgraded in future versions of the system. 117