SWAPON(8)                  Linux Programmer's Manual                 SWAPON(8)
NAME
       swapon, swapoff - enable/disable devices and files for paging and swap-
       ping

SYNOPSIS
       /sbin/swapon [-h -V]
       /sbin/swapon -a [-v] [-e]
       /sbin/swapon [-v] [-p priority]  specialfile ...
       /sbin/swapon [-s]
       /sbin/swapoff [-h -V]
       /sbin/swapoff -a
       /sbin/swapoff specialfile ...

DESCRIPTION
       Swapon is used to specify devices on which paging and swapping  are  to
       take place.

       The  device  or file used is given by the specialfile parameter. It may
       be of the form -L label or -U uuid to indicate a  device  by  label  or
       uuid.

       Calls  to swapon normally occur in the system multi-user initialization
       file /etc/rc making all swap devices available, so that the paging  and
       swapping activity is interleaved across several devices and files.

       Normally, the first form is used:

       -a     All  devices  marked  as ''swap'' swap devices in /etc/fstab are
              made available, except for those  with  the  ''noauto''  option.
              Devices that are already running as swap are silently skipped.

       -e     When  -a  is  used  with  swapon,  -e makes swapon silently skip
              devices that do not exist.

       -h     Provide help

       -L label
              Use the partition that has  the  specified  label.   (For  this,
              access to /proc/partitions is needed.)

       -p priority
              Specify  priority  for swapon.  This option is only available if
              swapon was compiled under and is used under  a  1.3.2  or  later
              kernel.  priority is a value between 0 and 32767. Higher numbers
              indicate higher priority. See swapon(2) for a  full  description
              of  swap  priorities.  Add  pri=value  to  the  option  field of
              /etc/fstab for use with swapon -a.

       -s     Display  swap  usage  summary  by  device.  Equivalent  to  "cat
              /proc/swaps".  Not available before Linux 2.1.25.

       -U uuid
              Use  the  partition  that  has  the  specified uuid.  (For this,
              access to /proc/partitions is needed.)

       -v     Be verbose.

       -V     Display version

       Swapoff disables swapping on the specified devices and files.  When the
       -a  flag  is  given, swapping is disabled on all known swap devices and
       files (as found in /proc/swaps or /etc/fstab).

NOTE
       You should not use swapon on a file with holes.  Swap over NFS may  not
       work.

SEE ALSO
       swapon(2), swapoff(2), fstab(5), init(8), mkswap(8), rc(8), mount(8)

FILES
       /dev/hd??  standard paging devices
       /dev/sd??  standard (SCSI) paging devices
       /etc/fstab ascii filesystem description table

HISTORY
       The swapon command appeared in 4.0BSD.

Linux 1.x                      25 September 1995                     SWAPON(8)