[CentOS] Swap = 0

Tue Apr 13 10:47:35 UTC 2010
Hakan Koseoglu <hakan at koseoglu.org>


2010/4/13 cahit Eyigünlü <cahit.eyigunlu at gmail.com>:
> is there any optimization tool i have added 2 more gb ram but it is still
> locking server :S
Which bit do you want to optimize?

> top - 13:11:13 up 33 min,  2 users,  load average: 29.96, 13.75, 10.97x
> Tasks: 280 total,  40 running, 236 sleeping,   0 stopped,   4 zombie
> Cpu(s): 61.1%us, 34.2%sy,  0.0%ni,  0.0%id,  0.0%wa,  0.3%hi,  4.4%si,
> 0.0%st
> Mem:   3090588k total,  2481096k used,   609492k free,    16068k buffers
> Swap:  2064376k total,    22796k used,  2041580k free,   274104k cached
Your server is pretty busy with such a high load, you might like to
throw more RAM and more CPU. 1/3d of the time is spent serving the
system itself. The IO waits are zero which is nice but you're still
spending a lot of time for the sys and si (software interrupts).

>  4331 root      18   0  169m 131m  764 S  0.0  4.3   0:01.75 /usr/sbin/clamd
>  4228 mysql     15   0  356m  53m 3904 S 24.0  1.8   5:42.20
> /usr/sbin/mysqld --basedir=/ --datadir=/var/lib/mysql --user=mys

Both of these are sleeping but you have to check why you have clamd
running. Do you serve files and require antivirus on the server?

If your server is a LAMP setup, serving php etc. with a mysql backend,
you might like to disable that.

Have a look at nmon from IBM and the analysis spreadsheet it has
(unfortunately that requires Windows Office, I never managed to get
that run successfully under OpenOffice). Nmon will collect the stats
and when you feed them to the analyser spreadsheet, you can see which
processes have grabbed the disk & CPU and when.

There are other tools out there as well but my preference has been
nmon for various other reasons (well, I have to deal with AIX boxes a
lot as well and it comes by default with the latest versions and it
works perfectly fine with CentOS and Debian/Ubuntu as well)..

You can run nmon with -t option (capacity planning, 15 min samples for
a day) or with customized options (don't forget -t for spreadsheet
Hakan (m1fcj) - http://www.hititgunesi.org