I am concerned about my server as I am seeing consistent CPU spikes in New Relic caused by DU. I am not having much help from the hosting company as they keep saying it is an application problem (however I got a little bit hopeful yesterday when someone actually looked into my server and and saw my APC memory was full up as the setting was only at 38mb.)

They adjusted it to 128mb. Since then the site performance has noticeably improved and the site feels more snappy.

I have started to notice the CPU spikes again which are consistent but site performance feels fine. Again it seems to be caused by DU (I am site owner so my knowledge is limited) see screenshot: DU (Root) CPU SPIKES

Here is an overview of the server over last 12 hours:

Server overview 12 hours

Apc stats

APC Stats

My server has 4gb ram and settings are as follows

PHP Memory - 2048mb APC - 128mb

Here is a screenshot from Top command. enter image description here

And the new relic server graphs around time of Top screenshot

enter image description here

Here are my cron jobs:

enter image description here

  • Strange behavior. Do you have SSH access to go in and see some detail from top, etc?
    – ddavidn
    Mar 24, 2015 at 18:33
  • Yes I do. The stats jump around alot so its hard to see exactly whats happening. I will try include a screenshot of TOP Mar 24, 2015 at 19:34
  • Top stats keep jumping around. I can't seem to freeze it to capture activity. Mar 24, 2015 at 22:33
  • Well, could it be related to a dashboard or monitoring of some kind, maybe installed by your hosting provider? I see Sensu running. Maybe it's polling du for information, though root is not a brilliant choice for running that. This is a dedicated server, correct?
    – ddavidn
    Mar 24, 2015 at 22:42
  • No its cloud hosting. Mar 24, 2015 at 22:49

1 Answer 1


Its clearly a cron task, likely that of whatever server control panel you are using.

du is a Linux utility for calculating disk usage of a given directory/file/path.

You could try a quick grep through the cron tasks, but if you are using something like cPanel/Plesk - its unlikely the command itself is likely to embedded within the cronjob itself.

grep -r "du " /etc/cron* /var/spool/cron/crontabs

On Debian/Ubuntu, /etc/cron.daily/apt is a likely candidate.

If you use ps ax | grep du at the time the process is running, you'll see more information about the process/command.

  • Hi. I have added screenshot of cron jobs. Thanks Mar 25, 2015 at 11:41

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