I am running VirtualBox (using the Qiime image http://qiime.org/install/virtual_box.html)

The physical hardware is a 32 core machine. The virtual machine in VirtualBox has been given 16 cores.

When booting I get:

Ubuntu 10.04.1 LTS
Linux 2.6.38-15-server

# grep . /sys/devices/system/cpu/*

# ls /sys/kernel/debug/tracing/per_cpu/
cpu0  cpu1  cpu10  cpu11  cpu12  cpu13  cpu14  cpu15  cpu2  cpu3  cpu4  cpu5  cpu6  cpu7  cpu8  cpu9

# ls /sys/devices/system/cpu/
cpu0  cpufreq  cpuidle  kernel_max  offline  online  possible  present  probe  release  sched_mc_power_savings

# echo 1 > /sys/devices/system/cpu/cpu6/online 
-su: /sys/devices/system/cpu/cpu6/online: No such file or directory

So it seems it detects the resources for 16 CPUs, but it only sets one online.

I have tested with another image that the VirtualBox host can run a guest with 16 cores. That works. So the problem is to trouble shoot the Qiime image to figure out why this guest image only detects 1 CPU.

  • 3
    Is it booting an SMP enabled kernel? uname -v should output something like "#1 SMP Thu May 3 14:46:44 UTC 2012"
    – George M
    May 11, 2012 at 14:23
  • Yes. #59~lucid1-Ubuntu SMP Mon Apr 30 23:56:18 UTC 2012
    – Ole Tange
    May 12, 2012 at 23:24
  • is IO_APIC enabled ?
    – daisy
    May 19, 2012 at 1:48
  • How do I test if IO_APIC is enabled?
    – Ole Tange
    May 20, 2012 at 12:09

2 Answers 2


It sounds like your VM has been configured to provide a single virtual cpu.

The following documentation might help you in reconfiguring your VM to provide multiple cores:


This may help, I had a similar issue with an Ubuntu VM. This help me with my original question

  • As mention in the question I already tried that.
    – Ole Tange
    May 20, 2012 at 1:51

QIIME came out with a new virtualbox image (version 1.5), which works.

If no one finds the answer to the problem above I will close the question in a week.

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