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 ALSOswapon(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)
