SWAPON(2)                 OpenBSD Programmer's Manual                SWAPON(2)

NAME
     swapon - add a swap device for interleaved paging/swapping



SYNOPSIS
     #include <unistd.h>

     int
     swapon(const char *special);

DESCRIPTION
     swapon() makes the block device special available to the system for allo-
     cation for paging and swapping.  The names of potentially available de-
     vices are known to the system and defined at system configuration time.
     The size of the swap area on special is calculated at the time the device
     is first made available for swapping.

RETURN VALUES
     If an error has occurred, a value of -1 is returned and errno is set to
     indicate the error.

ERRORS
     swapon() succeeds unless:

     [ENOTDIR]     A component of the path prefix is not a directory.

     [ENAMETOOLONG]
                   A component of a pathname exceeded {NAME_MAX} characters,
                   or an entire path name exceeded {PATH_MAX} characters.

     [ENOENT]      The named device does not exist.

     [EACCES]      Search permission is denied for a component of the path
                   prefix.

     [ELOOP]       Too many symbolic links were encountered in translating the
                   pathname.

     [EPERM]       The caller is not the super-user.

     [ENOTBLK]     special is not a block device.

     [EBUSY]       The device specified by special has already been made
                   available for swapping

     [EINVAL]      The device configured by special was not configured into
                   the system as a swap device.

     [ENXIO]       The major device number of special is out of range (this
                   indicates no device driver exists for the associated hard-
                   ware).

     [EIO]         An I/O error occurred while opening the swap device.

     [EFAULT]      special points outside the process's allocated address
                   space.

SEE ALSO
     config(8),  swapon(8)

BUGS
     There is no way to stop swapping on a disk so that the pack may be dis-
     mounted.

     This call will be upgraded in future versions of the system.

HISTORY
     The swapon() function call appeared in 4.0BSD.

OpenBSD 2.6                      June 4, 1993                                2