kvm_getswapinfo(3) [freebsd man page]

KVM_SWAPINFO(3) 					   BSD Library Functions Manual 					   KVM_SWAPINFO(3)

NAME

     kvm_getswapinfo -- return swap summary statistics for the system

LIBRARY

     Kernel Data Access Library (libkvm, -lkvm)

SYNOPSIS

     #include <kvm.h>

     int
     kvm_getswapinfo(kvm_t *kd, struct kvm_swap *, int maxswap, int flags);

DESCRIPTION

     The kvm_getswapinfo() function fills an array of kvm_swap structures with swap summary information for each swap device, for up to maxswap -
     1 devices.  The number of devices, up to maxswap - 1, is returned.  A grand total of all swap devices (including any devices that go beyond
     maxswap - 1) is returned in one additional array entry.  This entry is not counted in the return value.  Thus, if you specify a maxswap value
     of 1, the function will typically return the value 0 and the single kvm_swap structure will be filled with the grand total over all swap
     devices.  The grand total is calculated from all available swap devices whether or not you made room for them all in the array.  The grand
     total is returned.

     The flags argument is currently unused and must be passed as 0.

     If an error occurs, -1 is returned.

     Each swap partition and the grand total is summarized in the kvm_swap structure.  This structure contains the following fields:

	   char ksw_devname[];
	   int ksw_total;
	   int ksw_used;
	   int ksw_flags;

     Values are in PAGE_SIZE'd chunks (see getpagesize(3)).  ksw_flags contains a copy of the swap device flags.

CACHING

     This function caches the nlist values for various kernel variables which it reuses in successive calls.  You may call the function with kd ==
     NULL to clear the cache.

DIAGNOSTICS

     If the load average was unobtainable, -1 is returned; otherwise, the number of swap devices actually retrieved is returned.

     If the name of the swap device does not fit in the static char buffer in the structure, it is truncated.  The buffer is always zero termi-
     nated.

SEE ALSO

     kvm(3)

BSD
								 January 22, 1999							       BSD

SWAPON(8)						    BSD System Manager's Manual 						 SWAPON(8)

NAME

     swapon, swapoff, swapctl -- specify devices for paging and swapping

SYNOPSIS

     swapon [-F fstab] -aLq | file ...
     swapoff [-F fstab] -aLq | file ...
     swapctl [-AghklmsU] [-a file ... | -d file ...]

DESCRIPTION

     The swapon, swapoff and swapctl utilities are used to control swap devices in the system.	At boot time all swap entries in /etc/fstab are
     added automatically when the system goes multi-user.  Swap devices use a fixed interleave; the maximum number of devices is unlimited.  There
     is no priority mechanism.

     The swapon utility adds the specified swap devices to the system.	If the -a option is used, all swap devices in /etc/fstab will be added,
     unless their ``noauto'' or ``late'' option is also set.  If the -L option is specified, swap devices with the ``late'' option will be added
     as well as ones with no option.  If the -q option is used, informational messages will not be written to standard output when a swap device
     is added.

     The swapoff utility removes the specified swap devices from the system.  If the -a option is used, all swap devices in /etc/fstab will be
     removed, unless their ``noauto'' or ``late'' option is also set.  If the -L option is specified, swap devices with the ``late'' option will
     be removed as well as ones with no option.  If the -q option is used, informational messages will not be written to standard output when a
     swap device is removed.  Note that swapoff will fail and refuse to remove a swap device if there is insufficient VM (memory + remaining swap
     devices) to run the system.  The swapoff utility must move swapped pages out of the device being removed which could lead to high system
     loads for a period of time, depending on how much data has been swapped out to that device.

     Other options supported by both swapon and swapoff are as follows:

     -F fstab
	     Specify the fstab file to use.

     The swapctl utility exists primarily for those familiar with other BSDs and may be used to add, remove, or list swap devices.  Note that the
     -a option is used differently in swapctl and indicates that a specific list of devices should be added.  The -d option indicates that a spe-
     cific list should be removed.  The -A and -U options to swapctl operate on all swap entries in /etc/fstab which do not have their ``noauto''
     option set.

     Swap information can be generated using the swapinfo(8) utility, pstat -s, or swapctl -l.	The swapctl utility has the following options for
     listing swap:

     -h      Output values in human-readable form.

     -g      Output values in gigabytes.

     -k      Output values in kilobytes.

     -m      Output values in megabytes.

     -l      List the devices making up system swap.

     -s      Print a summary line for system swap.

	     The BLOCKSIZE environment variable is used if not specifically overridden.  512 byte blocks are used by default.

FILES

     /dev/{ada,da}?s?b	standard paging devices
     /dev/md?		memory disk devices
     /etc/fstab 	ASCII file system description table

DIAGNOSTICS

     These utilities may fail for the reasons described in swapon(2).

SEE ALSO

     swapon(2), fstab(5), init(8), mdconfig(8), pstat(8), rc(8)

HISTORY

     The swapon utility appeared in 4.0BSD.  The swapoff and swapctl utilities appeared in FreeBSD 5.1.

BSD
								 November 22, 2013							       BSD