xref: /dragonfly/lib/libc/sys/swapon.2 (revision 1de703da)
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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 1.2 2003/06/17 04:26:47 dillon 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 BUGS
108There is no way to stop swapping on a disk so that the pack may be
109dismounted.
110.Pp
111This call will be upgraded in future versions of the system.
112.Sh HISTORY
113The
114.Fn swapon
115function call appeared in
116.Bx 4.0 .
117