ultrix man page for swapon

swapon(2)							System Calls Manual							 swapon(2)

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

Syntax
       swapon(special)
       char *special;

Description
       The  system  call  makes the block device special available to the system for allocation for paging and swapping.  The names of potentially
       available devices 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.

Restrictions
       There is no way to stop swapping on a disk so that the pack may be dismounted.

Diagnostics
       The system call succeeds unless:

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

       [ENAMETOOLONG] A component of a pathname exceeded 255 characters, or an entire pathname exceeded 1023 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]      The 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 that no device driver exists for the associated hard-
		      ware.)

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

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

See Also
       config(8), swapon(8)

																	 swapon(2)