My host machine is Windows 7, running an Intel Core i5 Processor.

The Task Manager shows that I have 4 boxes under the Performance tab, which I assume to be 4 cores.

However on my OEL guest (on VirtualBox) /proc/interrupts only gives me a CPU0 column, suggesting that I only have one core.

Is this occurring because I am using virtual software?

[root@khadija ~]# cat /proc/cpuinfo
processor   : 0
vendor_id   : GenuineIntel
cpu family  : 6
model       : 42
model name  : Intel(R) Core(TM) i5-2410M CPU @ 2.30GHz
stepping    : 7
cpu MHz     : 2265.248
cache size  : 6144 KB
fpu     : yes
fpu_exception   : yes
cpuid level : 5
wp      : yes
flags       : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 syscall nx rdtscp lm constant_tsc up rep_good nopl pni monitor ssse3 lahf_lm
bogomips    : 4530.49
clflush size    : 64
cache_alignment : 64
address sizes   : 36 bits physical, 48 bits virtual
power management:

[root@khadija ~]# uname -a
Linux khadija.ahlanwsahlan.net 2.6.39-400.23.1.el6uek.x86_64 #1 SMP Wed May 8 16:37:12 PDT 2013 x86_64 x86_64 x86_64 GNU/Linux

2 Answers 2


The hypervisor presents a certain number of cores to the guest OS. I am not familiar with VirtualBox but I assume that it is quite similar to KVM/QEMU where you can configure the amount of cores (even above the number of physical ones).

Have a look at the settings of your VM.


Change the number of processors that are devoted to the guest VM under its settings dialog.


Doing so will definitely allocate more CPU cores to the guest VM.


  • Unfortunately this option is grayed out on my Oracle VM Virtualbox. VT-X is set as enabled in the BIOS.
    – user
    Nov 7, 2014 at 11:50
  • Another thing, I have been reading about ESXi recently. If I were to set up ESXi and then run virtual servers on top, would those virtual servers register all of my CPU cores as ESXi runs on 'bare metal?'
    – user
    Nov 7, 2014 at 11:50
  • @khadija - is your guest running? You have to stop it to get it un-grayed out. Also your host system has to have a CPU that allows it. Once you change it you can start the guest back up.
    – slm
    Nov 7, 2014 at 12:31
  • @khadija - I don't understand your 2nd Q here.
    – slm
    Nov 7, 2014 at 12:32
  • Great it is working, thanks. What I meant was that if I were to remotely access a server running ESXi, would the system specifications show that it had taken full advantage of the hardware? As in all CPU cores would be present etc.
    – user
    Nov 9, 2014 at 22:29

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .