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



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

SYNOPSIS
     swapon(special)
     char *special;

DESCRIPTION
     _S_w_a_p_o_n makes the block device _s_p_e_c_i_a_l available to the sys-
     tem 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 _s_p_e_c_i_a_l is calculated at the time the device is
     first made available for swapping.

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

ERRORS
     _S_w_a_p_o_n succeeds unless:

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

     [EINVAL]	    The pathname contains a character with the
		    high-order bit set.

     [ENAMETOOLONG] A component of a pathname exceeded 255 char-
		    acters, or an entire path name 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]	    _S_p_e_c_i_a_l is not a block device.

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

     [EINVAL]	    The device configured by _s_p_e_c_i_a_l was not con-
		    figured into the system as a swap device.

     [ENXIO]	    The major device number of _s_p_e_c_i_a_l is out of
		    range (this indicates no device driver exists



Printed 11/26/99	  March 9, 1986                         1






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



		    for the associated hardware).

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

     [EFAULT]	    _S_p_e_c_i_a_l points outside the process's allo-
		    cated address space.

SEE ALSO
     swapon(8), config(8)

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

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







































Printed 11/26/99	  March 9, 1986                         2