We've had an alert from Nagios on one of our servers that we have a runaway process. Logging in and running top doesn't show anything bad happening, but when I look at the output of ps I see something odd:

oxygen@mail-1:~$ ps -e -o %cpu,comm,cputime --sort %cpu | tail
 0.2 amavisd         00:00:11
 0.2 zmlogger        00:00:54
 0.2 zmstat-allprocs 03:44:19
 0.2 amavisd         00:00:07
 0.2 amavisd         00:00:14
 0.3 amavisd         00:00:08
 0.3 top             00:00:05
 0.5 amavisd         00:00:04
 8.1 mysqld          3-23:07:17
 7413 java            1184016091-02:47:13

%cpu and cputime don't look reasonable. Any ideas as to why this might be the case?

oxygen@mail-1:~$ ps --version
procps version 3.2.8
oxygen@mail-1:~$ uname -a
Linux mail-1 2.6.32-35-server #78-Ubuntu SMP Tue Oct 11 16:26:12 UTC 2011 x86_64 GNU/Linux

EDIT: Response to comments below:

Yes, good guess this is a Zimbra server.

Load averages are fairly high, this server is disk-bound:

top - 09:55:06 up 71 days,  3:23,  1 user,  load average: 4.03, 3.82, 3.60
Tasks: 301 total,   1 running, 300 sleeping,   0 stopped,   0 zombie
Cpu(s): 10.7%us,  1.7%sy,  0.0%ni, 59.3%id, 27.5%wa,  0.0%hi,  0.7%si,  0.0%st
Mem:   8192360k total,  7867364k used,   324996k free,   171704k buffers
Swap:  1953784k total,   950944k used,  1002840k free,  1619948k cached

pstree output as below

 oxygen@mail-1:~$ pstree
      │       └─sh───rotatelogs
      │       └─2*[sh───rotatelogs]
      │        ├─3*[cleanup]
      │        ├─2*[lmtp]
      │        ├─pickup
      │        ├─2*[proxymap]
      │        ├─qmgr
      │        ├─showq
      │        ├─3*[smtp]
      │        ├─6*[smtpd]
      │        ├─tlsmgr
      │        └─2*[trivial-rewrite]
      │              └─sleep

For what it's worth, it seems more like an overflow bug within ps than anything else. I can't think of any other way java would manage to consume 3 million years of cputime in 79 days!

  • Out of morbid curiosity, can you show us the three load averages? A pstree snapshot would also be nice. – Andrew B Jan 22 '13 at 1:33
  • What program is using Java? Any chance you are using Zimbra? – Lucas Kauffman Jan 22 '13 at 8:39
  • hmmmm... A computer that can do 3 million years worth of processing in 79 days sounds awesome... – drone.ah Jan 24 '13 at 16:26
  • Is this a virtual machine? If so, how much memory is committed to it? Are you using memory ballooning? I've seen some VMs showing crazy CPU usage when they were in fact fighting for memory in the Vmware host. – Giovanni Tirloni Sep 6 '14 at 22:44

I've just had a similar problem to this but with almost all processes showing extremely large CPU times immediately after a reboot.

You can make sure that it's not a problem with overflows in ps by looking at /proc/$PID/stat for the utime and stime columns (columns 14 and 15 on my kernel, check the proc(5) man page to see if yours are different), e.g.:

cut -d' ' -f14,15 /proc/$PID/stat

These are numbers of clock ticks, and if it's not a problem with ps, they will be extremely large values.

I'm running Scientific Linux 6.4 (a RHEL based distro) and saw the problem with kernel-2.6.32-358.6.2.el6.x86_64.

I fixed it by installing a newer version of the kernel (kernel-2.6.32-431.el6.x86_64) and rebooting.

I see that similar problems have been reported for various distributions:

So upgrading is probably the best way to fix the problem.


Install sysstat (at least that is the Linux package) and run sar for a week or so, then analyze it's logs/statistics. That gives you a longer time view, not just a snapshot whenever you happen to notice and log in.

Anything strange in the logs, not just for the system itself but for the different applications you are running?

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