LinuxQuestions.org
Go Job Hunting at the LQ Job Marketplace
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Server
User Name
Password
Linux - Server This forum is for the discussion of Linux Software used in a server related context.

Notices

Reply
 
Search this Thread
Old 08-19-2010, 09:26 AM   #1
c0m4r
LQ Newbie
 
Registered: May 2009
Posts: 9

Rep: Reputation: 0
Iowait indication


Hi,

Is this possible to check which process or processess is responsible for high percent of iowait (%wa in top). I mean, I know that iowait measures CPU performance, not I/O but it depends directly on the hdd operations (f.e. copying). In other words I would like to check which process is generating hdd load.

Best regards,
Andrew
 
Old 08-19-2010, 10:47 AM   #2
quanta
Member
 
Registered: Aug 2007
Location: Vietnam
Distribution: RedHat based, Debian based, Slackware, Gentoo
Posts: 724

Rep: Reputation: 100Reputation: 100
As my understand, it may be:
Code:
ps -eo pid,user,state,command | awk '$3 ~ /D/ {print $0}'
or: http://www.linuxquestions.org/questi...4/#post3316917
 
1 members found this post helpful.
Old 08-19-2010, 07:51 PM   #3
c0m4r
LQ Newbie
 
Registered: May 2009
Posts: 9

Original Poster
Rep: Reputation: 0
This is exactly what I looked for and really good lecture to read. Thank you very much quanta.
 
Old 08-19-2010, 08:33 PM   #4
syg00
LQ Veteran
 
Registered: Aug 2003
Location: Australia
Distribution: Lots ...
Posts: 12,042

Rep: Reputation: 970Reputation: 970Reputation: 970Reputation: 970Reputation: 970Reputation: 970Reputation: 970Reputation: 970
So long as you only use it as an indication. As you said, this is really looking at things the wrong way around.
It is easy to construct situations where several tasks are "waiting" for I/O, but only one is contributing almost all the load. That can only really be checked by something like blktrace which is at the VFS layer.

Something else you might be interested in is iotop - very nice python script. Seems to be in most distros these days.

Last edited by syg00; 08-19-2010 at 08:34 PM.
 
1 members found this post helpful.
Old 08-20-2010, 10:24 AM   #5
c0m4r
LQ Newbie
 
Registered: May 2009
Posts: 9

Original Poster
Rep: Reputation: 0
Yes. I know that what "ps" will show me with state "D" is not really what I am looking for, but it is already much more information than iowait alone gives me. Iotop seems to be exactly what I need, I'll check it. Thanks syg00.
 
  


Reply

Tags
hdd, iowait, load


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Indication of kernel's initialisation end pmil Linux - Kernel 3 12-11-2009 06:07 AM
Original Poster Indication is Great! blackhole54 LQ Suggestions & Feedback 12 06-01-2009 10:07 PM
Searching for app: cp with status indication tle02 Linux - Software 2 03-30-2006 05:17 AM
Iowait ashley75 Linux - General 25 02-11-2006 11:41 PM
Eth link up/down indication prital Linux - Networking 2 11-30-2005 04:58 AM


All times are GMT -5. The time now is 08:04 AM.

Main Menu
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration