why cpu load is too much with virtualbox

eboy98 · 02-16-2010, 01:17 AM

hello there,

recently i have installed VirtualBox-3.1-3.1.4.This is the first time i am using virtual machine.Fact is after i start the guest OS....with top from host OS i found cpu load is around 60-80% and memory load 20-30% is it normal and is it safe to run for long time.If possible please check the attached image.

Configurations:

HOST OS: RHEL5

processor : 0
vendor_id : GenuineIntel
cpu family : 15
model : 2
model name : Intel(R) Pentium(R) 4 CPU 2.66GHz
stepping : 9
cpu MHz : 2666.635
cache size : 512 KB
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 sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe up pebs bts cid xtpr
bogomips : 5335.99
clflush size : 64

Physical RAM: 765 MB
Video RAM: 128 MB

GUEST OS: RHEL5(text-mode)

Hard Disk : 5 GB
ALLOCATED RAM : 200 MB
ALLOCATED VRAM: 12 MB
Device: 1 dvd drive, 1 NIC card

neonsignal · 02-16-2010, 02:17 AM

They are reasonably high CPU loads, but it isn't going to damage the computer. The CPU is designed to run continuously at 100% load, as long as the cooling systems are working properly (and the CPU is not overclocked).

The memory load looks pretty normal, but the CPU load is not. There may be some ways to improve it:

1. Add the following to the grub defoptions of the guest to decrease the speed of the kernel clock (not forgetting to run update-grub afterwards):

Code:

divider=10 clocksource=acpi_pm

2. Install the VirtualBox guest additions, which will improve the efficiency of the drivers.

eboy98 · 02-16-2010, 04:09 AM

Hay neonsignal,

Thank you for so quick answer.

1.about the following line ..should I add to guest os grub.conf file.

Code:

divider=10 clocksource=acpi_pm

2.How can I Install the VirtualBox guest additions.

neonsignal · 02-16-2010, 06:05 PM

In the grub menu /boot/grub/menu.lst of the guest, you will find the following line:

Code:

# defoptions=

Change this to:

Code:

# defoptions= divider=10 clocksource=acpi_pm

And then run update-grub (and reboot). This will add those options to the kernel line for your default kernel inside the guest (which I assume is the one you use). You can just add the options directly to the kernel line, but a later update-grub will overwrite them.

Installing the guest additions on older distros is a bit more effort. You will find a number of guides for RHEL/CentOS (on newer distros it has been put into the package repositories).

eboy98 · 02-17-2010, 12:23 AM

CPU load problem been solved.what i have done:

1.follow this site http://n8wood.wordpress.com/2009/04/...-centos-guest/

2.install new kernel 2.6.23.17

3.check the following fact.

Code:

    Under Processor Type and Features:

    Tickless System (Dynamic Ticks) = YES

    Paravirtualized guest support = YES

    Timer Frequency = 100 HZ

4.compile it
5.problem solved(though it took 2.5 hr to complete)

now cpu load around 5-15 %