Trouvé ici :
http://www.host.co.in/forums/f20/spri-system-priority-435/
SPRI – changes the priority of different processes in accordance to level of importance, hence increasing server performance.
SPRI (System Priority) is a utility designed to que different processes with different priority levels based on 3 class levels of importance (high,med,low).
The problem? Linux has priority levels to thread all tasks at, these prio’s are ranged from -20 to +19 (negative = high prio, positive = low prio) with 0 as the default for all processes. So this being the fact, with everything operating at prio 0 you got fights between services as to who gets what resources first.
Solution? Very simply, que different processes at different priority levels to effectively discipline the system on who gets what resource access first.
The average load level of a server can be substantialy decreased by using spri, by as much as 5-20%, of course results may vary.
Download the current release of SPRI distributed under the GNU GENERAL PUBLIC LICENSE:
– http://www.r-fx.ca/downloads/spri-current.tar.gz
Setup
To setup SPRI, simply execute the ‘install.sh’ script inside the extraced path.
This will install spri to /usr/local/spri, and symlink its executable to
/usr/local/sbin/spri. As well, there will be a cron.d entry added to
/etc/cron.d/spri, set to run it once every 45 minutes.
Usage
SPRI has very straight forward usage and configuration. First you should edit
the preset of class rules provided with SPRI. The files are located at:
/usr/local/spri/high
/usr/local/spri/med
/usr/local/spri/low
The priority associated with each level is defined in the conf.spri file. Once
all options are to your satisfaction you should run spri to test it. There is
two command line arguments for spri
-v Verbose output
-q Quiet; no output
Execute ‘/usr/local/sbin/spri -v’ and observe it’s actions. Make any tweaks you
see fit to the config file or priority discipline files and then your set to go