SWAPON(2)                                                            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 system for allo‐
       cation 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 characters, 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 configured 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 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  allocated  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 dis‐
       mounted.

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



4th Berkeley Distribution        March 9, 1986                       SWAPON(2)