Provided by: swapd_0.2-10_i386 bug

NAME

       swapd - dynamic swapping manager

SYNOPSIS

       swapd  [-h]  [--help]  [--copyright]  [--config  file]  [--maxswaps  n]
       [--memlimit  kb]  [--mkswap  path]  [--pause  msec]  [--pidfile   file]
       [--swapdir dir] [--swapsize kb] [--timeout sec]

DESCRIPTION

       swapd  is  a  dynamic  swapping manager. It provides the system with as
       much swap space (virtual memory) as is required at a particular time by
       dynamicly creating swap files. This is more convinient than using fixed
       swap files and/or partitions because they (a) are unused  most  of  the
       time  and  are  just  taking  up  disk space; and (b) provide a limited
       amount of virtual memory.

OPTIONS

       All values given on the command line will override config file  values.

       -h, --help      Displays the command line help.

       --copyright     Displays the copyright notice.

       --config file   Location of an alternate configuration file.

       --maxswaps n    Maximum number of swap files. No more than n swap files
                       will be used. The default is 8 (as many as the  default
                       kernel will allow).

       --memlimit kb   Memory  limit  in  kilobytes.  When the total amount of
                       free memory gets below this number, swapd creates a new
                       swap file.

       --mkswap path   Location of mkswap(8), usually /sbin/mkswap.

       --pause msec    Pause  between  memory  checks in miliseconds (when the
                       total amount of free memory is above memlimit).

       --pidfile file  Location of the PID file, usually /var/run/swapd.pid.

       --swapdir dir   Swap directory where all the swap files are kept.

       --swapsize kb   Swap file size (>=64k).

       --timeout sec   Timeout. If the last created swap file  is  unused  for
                       sec  seconds,  it  will  be  removed.  The last created
                       swapfile is considered unused when there are more  than
                       memlimit  +  swapsize  kb  of  free  memory (physical +
                       swap).

CONFIGURATION

       This is an example configuration file:

       # swapd.conf - config file for swapd
       #
       # Copyright 2000 Neven Lovric <nlovric@jagor.srce.hr>
       #

       # Memory limit in kilobytes.
       # When the total amount of free memory gets below this number, swapd creates
       # a new swap file.
       # 16384 or more recommended
       memlimit 16384

       # Pause between memory checks in miliseconds.
       # When the total amount of free memory is above <memlimit>, swapd will pause
       # for <pause> miliseconds before checking memory again.
       # 1000 should be ok for most systems
       pause 1000

       # Swap file size in kilobytes.
       # >= 64, 4096 recommended
       swapsize 4096

       # Maximum number of swap files.
       # No more than <maxswaps> swap files will be used.
       # 0 = unlimited (as many as the kernel will allow)
       # 8 = how many a default kernel allows
       maxswaps 8

       # Timeout in seconds.
       # If the last created swap file is unused for <sec> seconds, it will be
       # removed. The last created swapfile is considered unused when there are
       # more than <memlimit> + <swapsize> kb of free memory (physical + swap).
       # 60 is nice
       timeout 60

       # Swap directory where all the swap files are kept.
       swapdir /swap

       # PID file (where the currently running swapd stores it’s PID so a new swapd
       # can find it)
       pidfile /var/run/swapd.pid

       # Full path to mkswap.
       mkswap /sbin/mkswap

PERFORMANCE

       The most important parameter which may drasticly effect performance  is
       the  memory  limit.  If  the  memory limit is low, (1) there may not be
       enough memory ready for a program to allocate at once or (2) swapd  may
       not  be  able  to create new swap files before we run out of memory. If
       your programs are running out of memory, it will primarily be due to  a
       low  memory  limit.  If you really want to have a low memory limit, you
       should decrease the swap size and pause.

       The second important parameter is the swap size. If you choose  to  use
       bigger  swap  files,  you  may experience slowdowns when swap files are
       created. On the other hand, small swap files may lower performance when
       there are many of them. The important thing is not to make them too big
       to create before we run out of memory.

       Another important parameter is the pause, which should  be  shorter  on
       faster  systems.  If  it  is  too  long, swapd may fail to detect rapid
       memory changes and therefore fail to create new swap  files  when  they
       are  needed.  However, if you notice swapd is constantly using too much
       CPU, increase the pause.

FILES

       /etc/swapd.conf
       /var/run/swapd.pid
       /etc/init.d/swapd
       SWAPDIR/linux*.swp

BUGS

       Might fail if swapping over NFS

SEE ALSO

       mkswap(8), swapon(8), swapoff(8), free(8)

MAINTAINER

       Aigars Mahinovs <aigarius@debian.org>

AUTHOR

       Neven Lovric <nlovric@linux.hr>

       The latest upstream version is available via anonymous ftp:

              ftp://ftp.linux.hr/pub/swapd