virtualbox.org

(in reference to http://forums.virtualbox.org/viewtopic.php?f=7&t=20186)

I have a fairly old RU system, a Dell PowerEdge 2650 running Dual Xeon dual-core CPU's. I setup VirtualBox 3.02, and noticed Guest VM's will only show 1 CPU in top:

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Cpu0  : 45.9%us, 48.6%sy,  0.0%ni,  0.0%id,  0.0%wa,  1.8%hi,  3.7%si,  0.0%st

whereas the Host system shows all 4:

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Cpu0  :  1.2%us,  3.3%sy,  0.0%ni, 90.9%id,  4.6%wa,  0.0%hi,  0.1%si,  0.0%st
Cpu1  :  1.2%us,  4.5%sy,  0.0%ni, 93.1%id,  1.1%wa,  0.0%hi,  0.1%si,  0.0%st
Cpu2  :  0.5%us,  2.8%sy,  0.0%ni, 96.3%id,  0.4%wa,  0.0%hi,  0.0%si,  0.0%st
Cpu3  :  1.1%us, 60.1%sy,  0.0%ni, 38.7%id,  0.1%wa,  0.0%hi,  0.0%si,  0.0%st

Monitoring the host CPU's it looks like only one core is every used, and the usage rotates through each of the 4 cores, but never uses more than one at a time. Of course I also can't change the number of CPU's used in the Guest settings, it is set to 1 and I can't increase the value.

I have confirmed that this system doesn't support Intel VT-x (I think Dell call it Hyper-V and it wasn't available until PE2850's), and googling around a bit seems to say that there's nothing I can do, there's no way for VirtualBox VM's (or any VM service) to see all of the CPU's without some sort of hardware virtualization support.

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cat /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 15
model           : 2
model name      : Intel(R) Xeon(TM) CPU 3.06GHz
stepping        : 9
cpu MHz         : 3056.839
cache size      : 512 KB
physical id     : 0
siblings        : 2
core id         : 0
cpu cores       : 1
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 2
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe cid xtpr
bogomips        : 6115.56

Can anyone confirm this?

It seems to me that this system is basically useless for virtualization if only one CPU, or one core, can be utilised by any Guest VM

Also, can anyone confirm that in this situation, each VM will only have available 25% of the processing power that the system can provide?

Thanks in advance for any help...

Hi dude, I've exactly the same Server to test my VirtualBox installation etc.

Yes you only can attach one cpu per VM, it's due to the Intel-VT instruction which is not use on this processor family.

But I think that the Cpu wich is attach t the VM can use 100% of each processor because on my machine I have 4 VMs who use 100% of his CPU and on the Host I see 100% of my 4 physical CPU used.

You use 100% of one core with one VM. Running 1 VM with 100% CPU usage inside the VM will result in a 25% use on the Host. After all, if you have 4 cores, and one is on full load, you have three cores doing nothing, which translates to 25% of total processing power in use. Two VMs will generate 50% use, etc.

The technology you refer to as Dells' name isn't right, it's from Microsoft. It's in their Server 2008 system that's called Hyper-V. That is a different virtualization option that can be used, much like Xen. Only this runs on Windows, and it needs hardware accelerated virtualization from the processors.

Thanks to you both for replying

But I think that the Cpu wich is attach t the VM can use 100% of each processor because on my machine I have 4 VMs who use 100% of his CPU and on the Host I see 100% of my 4 physical CPU used.

In my setup I see the host only ever using one core of one CPU at a time for a single VM. The core being used changes every 5-20 seconds, like the host is sharing out the load.

You use 100% of one core with one VM. Running 1 VM with 100% CPU usage inside the VM will result in a 25% use on the Host. After all, if you have 4 cores, and one is on full load, you have three cores doing nothing, which translates to 25% of total processing power in use. Two VMs will generate 50% use, etc.

This sounds more like what I'm seeing. Thanks. At least I can run 4 VM's and use the resources available.

virtualbox.org

System with no Intel VT-x support (Dell PE2650)

System with no Intel VT-x support (Dell PE2650)

Re: System with no Intel VT-x support (Dell PE2650)

Re: System with no Intel VT-x support (Dell PE2650)

Re: System with no Intel VT-x support (Dell PE2650)