High CPU usage after latest VM upgrade

Submitted by Rogi on Thu, 10/22/2009 - 09:26

The high CPU usage is being caused by the VM stats collection script. My CPU averages are now around 0.40 instead of the usual 0.07 to 0.10 (ish).

Processor is a Xeon L5420 @ 2.50GHz (4 cores).

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Comments

Submitted by Rogi on Thu, 10/22/2009 - 10:27

Have had to shut down VM status collection.

Submitted by Rogi on Thu, 10/22/2009 - 11:02

It's webmin itself causing the high CPU after the latest upgrade. Disabling status collection made no difference.

Submitted by andreychek on Thu, 10/22/2009 - 11:08

Can you run "ps auxw", and attach the resulting output as a text file to this request?

Also, can you paste in the output of this command:

top -n 1 | head -25

Thanks!

Submitted by andreychek on Thu, 10/22/2009 - 11:41

Okay, here's the two things I noticed --

First, collectinfo still seems to be running, and is at the top of your "top" output. It seems to be using up a decent chunk of CPU there.

Second, I don't see a new copy of Webmin running -- the one open on your server there was launched on October 4th. Even so, it's only using some 6MB of RAM, and no CPU time, so it doesn't seem to be the cause of the slowness issues you're seeing.

If you recently upgraded Webmin/Virtualmin, you may want to make sure you've got the latest version up by running this command: /etc/init.d/webmin restart

Submitted by Rogi on Thu, 10/22/2009 - 12:00

Ok, thanks for the replies.

I have restarted webmin, which is good, but as you say it wasn't the culprit.

It's the collectinfo.pl script that is pushing the CPU average up (a lot) since today's update of VM. It now takes, at a guess, about 5-8 times longer to run each time and during that time uses up a full 100% of one core.

Maybe it needs a quick looking at to see what's up with it in this latest release?

Submitted by JamieCameron on Thu, 10/22/2009 - 12:17

I think the issue here is that in Virtualmin 3.74, we also collect and report on all available packages .. which on some systems can be quite high.

To see if this is the cause, edit /usr/share/webmin/virtual-server/collect-lib.pl and remove lines 84 and 85, which read :

        local @allposs = &security_updates::list_possible_updates(2, 1);
        $info->{'allposs'} = \@allposs;