Comments on: How do I find out Linux Disk utilization?

By: soundar

soundar — Thu, 09 Feb 2012 12:55:26 +0000

where x = device

example : iostat -x -d sda 5

By: Reza

Reza — Fri, 02 Sep 2011 17:03:19 +0000

Very useful… thanks!

By: Joseph Taiwo

Joseph Taiwo — Tue, 09 Aug 2011 06:08:42 +0000

Hi,

My company uses a VPS hosted in softlayer. Anytime Irun iostat, I hadly get any of these data. Could it be a problem with the VPS?
The sample of the command output for iostat -d -x 5 3 is as below:

Device:         rrqm/s   wrqm/s   r/s   w/s   rsec/s   wsec/s avgrq-sz avgqu-sz   await  svctm  %util
Device:         rrqm/s   wrqm/s   r/s   w/s   rsec/s   wsec/s avgrq-sz avgqu-sz   await  svctm  %util
Device:         rrqm/s   wrqm/s   r/s   w/s   rsec/s   wsec/s avgrq-sz avgqu-sz   await  svctm  %util

Please I will like to know if there is a way around this. Thanks

By: Lars

Lars — Tue, 26 Jul 2011 09:05:58 +0000

Great article. Just a quick note. On one of our older Debian servers we had to install sysstats package to use iostat.

By: David Ward

David Ward — Mon, 16 Aug 2010 05:03:56 +0000

I should use my gravatar email address :)

By: David Ward

David Ward — Mon, 16 Aug 2010 05:03:06 +0000

Great article. Thanks!

I too would like to know what is “high”

Also, how do you follow on from this. I have had massive IO wait issues at times and tracking down the process causing the issue is very hard. Any tips in this direction?

Thanks

By: Dave Neary

Dave Neary — Tue, 09 Feb 2010 11:28:23 +0000

Hi!

Thanks for the information, very useful.

I have one question – what constitutes “high” for r/s & w/s? Is over 10 high? Over 100, 1000?

I suspect that a hard disk is slowing down on me – whenever there is an I/O intensive operation (swapping, download, starting Firefox or OOo, things like that), everything slows to a crawl, including process switching.

Is there a way to find out from iostat what bandwidth the disk is giving me? What is the real latency of a disk?

Thanks!
Dave.

By: arumon

arumon — Thu, 03 Sep 2009 11:48:15 +0000

good artice!!!!
one question, Please tell what is the use of the below specified files.
/sys/block/sda/queue/iosched/queued
/sys/block/sda/queue/nr_requests
/sys/block/sda/device/queue_depth

By: whall

whall — Thu, 27 Aug 2009 21:43:46 +0000

Mike – you need to not specify “-d”. Only use -d if you’re going to specify a disk like sda or sdb. Just use the -x interval.

ie, iostat -x 10

means it will immediately give one output that represents from boot to now, and then every 10 seconds it will output a line that represents the last 10 seconds, and it will repeat forever.

You can also take this into excel and graph it, paying attention to the 4-5 columns the author mentioned.

By: Ash Sethi

Ash Sethi — Wed, 21 May 2008 06:31:02 +0000

Another good article… thanks for sharing,

By: Mike

Mike — Sat, 01 Mar 2008 13:23:56 +0000

When I enter the command “iostat -d -x 5 3″ I do not get any statistics. Here is what I get:

# iostat -d -x 5 3
Linux 2.4.33.3 (FILES) 03/01/2008

Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util

Any ideas on what the problem could be? I’m running Slackware 11.0 with the stock kernel.

Thanks in advance.

By: Rishi kapur

Rishi kapur — Fri, 29 Feb 2008 05:54:52 +0000

Please suggest me – system load average is shooting.

%iowait is high and found with iostat output one disk mentioned below may be the cause.

Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
cciss/c0d0 2269.60 132.60 296.20 77.60 20521.60 1681.60 10260.80 840.80 59.40 4.15 11.18 2.65 99.20

please suggest