Re: can I measure IO per process?

Henry Poras said,on my timestamp of 15/02/2006 2:43 AM:

> I'm currently running on RedHat AS3. On one of our boxes I noticed the
> CPU was spending most of its time with 'wait io' (wa column in vmstat
> was 85%-95%). The servicetime as seen from iostat -dk -x was also high,
> so this was a problem. What I couldn't figure out, and what would be
> very useful, was how to associate the io with specific processes. Is
> there a way to do this?

AFAIK, in RHAS3 this is not possible. If I understood correctly and you want io by os process.

What you can do is use iostat by device. As in: iostat -d -k -x /dev/sda1 -x /dev/sdb1 -x /dev/sda2 -x /dev/sdb2 10 1000 etcetc...
Where each one of the "-x /dev/s*" is each of the mounted file systems.

Assuming you have a good spread of database and other files across file systems, you can then indirectly see which is/are getting the large waits. And by extrapolation, the program(s) that use(s) such.

-- 
Cheers
Nuno Souto
dbvision_at_iinet.net.au
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