SAR utility to monitor cpu utilization.

Downloaded Sar from below url.

http://sebastien.godard.pagesperso-orange.fr/download.html

I found it little difficult to install rpm(sysstat-10.0.0-1.i586.rpm) so i moved my attention to install sysstat-10.0.0.tar.gz using make install method.

# ls -ltr
total 328
-rw-r--r-- 1 root root 330646 May 3 13:09 sysstat-10.0.0(2).tar.gz
# gunzip sysstat-10.0.0\(2\).tar.gz
# ls -ltr
total 1796
-rw-r--r-- 1 root root 1832960 May 3 13:09 sysstat-10.0.0(2).tar
# tar -xvf sysstat-10.0.0\(2\).tar
# ls -ltr
total 1800
drwxr-xr-x 8 501 501 4096 Mar 14 01:16 sysstat-10.0.0
-rw-r--r-- 1 root root 1832960 May 3 13:09 sysstat-10.0.0(2).tar


The simplest way to compile this package is:

1. `cd' to the directory containing the package's source code
# cd sysstat-10.0.0
Now type
`./configure' to configure the package for your system.
#./configure
If you're
using `csh' on an old version of System V, you might need to type
`sh ./configure' instead to prevent `csh' from trying to execute
`configure' itself.

Running `configure' takes awhile. While running, it prints some
messages telling which features it is checking for.

2. Type `make' to compile the package.
#make
3. Optionally, type `make check' to run any self-tests that come with
the package.(Not very Important)

4. Type `make install' to install the programs and any data files and
documentation.
#make install

5. You can remove the program binaries and object files from the
source code directory by typing `make clean'. To also remove the
files that `configure' created (so you can compile the package for
a different kind of computer), type `make distclean'. There is
also a `make maintainer-clean' target, but that is intended mainly
for the package's developers. If you use it, you may have to get
all sorts of other programs in order to regenerate files that came
with the distribution.
(Source of information: INSTALL file that comes bundled with sar utility)


Install various dependencies from Distribution CD.(This is only required if above installation is failed due to dependencies. )

Everything You need to know about SAR is written in below article.

Lets explore more into SAR.

Let monitor the CPU utilization for some time .Gathering a cpu stat at a point makes no sense so continuous gathering has its own advantages .
Say in below command cpu is observered 10 times in an interval of 2 seconds.

# sar 2 10
Linux 2.6.18-92.el5 (OEL-5.2-32bit) 04/06/2011 _i686_ (1 CPU)

03:45:19 PM CPU %user %nice %system %iowait %steal %idle
03:45:21 PM all 0.00 0.00 0.51 0.00 0.00 99.49
03:45:23 PM all 0.00 0.00 0.51 0.00 0.00 99.49
03:45:25 PM all 0.00 0.00 0.51 0.00 0.00 99.49
03:45:27 PM all 0.00 0.00 1.01 0.00 0.00 98.99
03:45:29 PM all 0.00 0.00 1.01 0.00 0.00 98.99
03:45:31 PM all 0.00 0.00 0.00 0.00 0.00 100.00
03:45:33 PM all 0.00 0.00 1.01 0.00 0.00 98.99
03:45:35 PM all 0.00 0.00 0.00 0.00 0.00 100.00
03:45:37 PM all 0.00 0.00 1.01 0.00 0.00 98.99
03:45:39 PM all 0.00 0.00 1.01 0.00 0.00 98.99
Average: all 0.00 0.00 0.66 0.00 0.00 99.34

The most important row from above output is the one which displays average of cpu utilization(highlighted in bold).
The Most Important column from above output is the one which displays idle cpu(Since my machine is just a sar utility testing machine ,i m not getting any cpu utilization .In short most of the time my cpu is idle).

Now its time to generate some load on CPU and then examine the output of SAR.
created a simple scipt with name cpuload.sh .
#!/bin/bash

while : ; do
true
done
and executed it in background using .
# ./cpuload.sh &

Ran above sar command one more time and examined the output.

# sar 2 10
Linux 2.6.18-92.el5 (OEL-5.2-32bit) 04/06/2011 _i686_ (1 CPU)

04:21:31 PM CPU %user %nice %system %iowait %steal %idle
04:21:33 PM all 100.00 0.00 0.00 0.00 0.00 0.00
04:21:35 PM all 99.50 0.00 0.50 0.00 0.00 0.00
04:21:37 PM all 99.49 0.00 0.51 0.00 0.00 0.00
04:21:39 PM all 99.49 0.00 0.51 0.00 0.00 0.00
04:21:41 PM all 100.00 0.00 0.00 0.00 0.00 0.00
04:21:43 PM all 98.99 0.00 1.01 0.00 0.00 0.00
04:21:45 PM all 99.49 0.00 0.51 0.00 0.00 0.00
04:21:47 PM all 99.49 0.00 0.51 0.00 0.00 0.00
04:21:49 PM all 99.49 0.00 0.51 0.00 0.00 0.00
04:21:51 PM all 99.49 0.00 0.51 0.00 0.00 0.00
Average: all 99.55 0.00 0.45 0.00 0.00 0.00

Now its time to find the culprit behind the cpu load.
Below command displays top 10 cpu utilized processes.

# ps -auxf | sort -nr -k 3 | head -10
Warning: bad syntax, perhaps a bogus '-'? See /usr/share/doc/procps-3.2.7/FAQ
root 4962 87.6 0.1 4476 964 pts/1 R 16:18 4:15 \_ /bin/bash ./cpuload.sh
root 309 0.5 0.0 0 0 ? S< 15:40 0:14 \_ [kjournald]
root 4663 0.2 0.1 1948 644 ? S 15:42 0:05 \_ hald-addon-storage: polling /dev/hdc
root 4844 0.1 0.8 27388 4140 ? Sl 15:42 0:03 /usr/libexec/gdm-rh-security-token-helper
root 4224 0.1 2.0 42336 10580 ? Ssl 15:42 0:03 /usr/bin/python -E /usr/sbin/setroubleshootd
root 1 0.1 0.1 2064 620 ? Ss 15:40 0:03 init [5]
xfs 4572 0.0 0.3 3928 1700 ? Ss 15:42 0:00 xfs -droppriv -daemon
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
smmsp 4518 0.0 0.2 8052 1484 ? Ss 15:42 0:00 sendmail: Queue runner@01:00:00 for /var/spool/clientmqueue
rpc 4211 0.0 0.1 1808 608 ? Ss 15:42 0:00 portmap

Examine the entry in bold.

Now its time to terminate the script .
# ps -ef | grep cpuload
root 4962 4875 89 16:18 pts/1 00:04:55 /bin/bash ./cpuload.sh
root 4987 4875 0 16:23 pts/1 00:00:00 grep cpuload
Kill it using process id.
# kill -9 4962

CPU is back to normal again.

# sar 2 10
Linux 2.6.18-92.el5 (OEL-5.2-32bit) 04/06/2011 _i686_ (1 CPU)

04:24:13 PM CPU %user %nice %system %iowait %steal %idle
04:24:15 PM all 0.00 0.00 0.51 0.00 0.00 99.49
04:24:17 PM all 0.00 0.00 0.00 0.00 0.00 100.00
04:24:19 PM all 0.00 0.00 0.00 0.00 0.00 100.00
04:24:21 PM all 0.00 0.00 0.50 0.00 0.00 99.50
04:24:23 PM all 0.00 0.00 0.00 0.00 0.00 100.00
04:24:25 PM all 0.00 0.00 0.50 0.00 0.00 99.50
04:24:27 PM all 0.00 0.00 0.00 0.00 0.00 100.00
04:24:29 PM all 0.00 0.00 0.00 0.00 0.00 100.00
04:24:31 PM all 0.00 0.00 0.00 0.00 0.00 100.00
04:24:33 PM all 0.00 0.00 1.01 0.00 0.00 98.99
Average: all 0.00 0.00 0.25 0.00 0.00 99.75

Find more info Here.

http://www.thegeekstuff.com/2011/03/sar-examples/?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+TheGeekStuff+%28The+Geek+Stuff%29

Please Leave us with your comments and Queries/Suggestions.
           I will try to reply asap.