On Tue, 19 May 2009, Yakoob, M. Kazi M. wrote:
> replying your first email ... SAR for system activity report.
>
> not to your detailed reply in your second email.
>
> The result you sent me is my expected result too; but what i think this
> command give a different output in Ubuntu.
>
> I updated the system and still the output is same.
>
> now; i need to know how manually can i calculate %util ...
>
> Thanks in advance ...
>
> Regards,
> Kazi
>
On my Gentoo machine, i just extracted the source code of
sysstat 8.0.4
Here is an excerpt from the FAQ
Because of a Linux kernel bug, iostat -x may display huge I/O
response times (svctm) and a bandwidth utilization (%util) of
100% for some devices.
Indeed these devices have a value for the field #9 (beginning
after the device name) in /proc/{partitions,diskstats} which
is always different from 0, and even negative sometimes.
Yet this field should go to zero, since it gives the
number of I/Os currently in progress (it is incremented as
requests are submitted, and decremented as they finish).
To (temporarily) solve the problem, you should reboot your
system to reset the counters in /proc/{partitions,diskstats}.
working with this macro,
#define S_VALUE(m,n,p) (((double) ((n) - (m))) / (p) * HZ)
please see the Twincling pastebin for the relevant code,
i've highlighted it for you at
http://twincling.pastebin.com/f67d42ace
Hope this helps.
thanks
Saifi.
