Hi,
I just closed a service-request with sun. Topic: Why is Win32 slower running with two CPUs under VBox 3 than running with one CPU on VBox 2?
I am running VBox on CentOS 5 64 bit (AMD Athlon Dual Core).
The problem is - according to sun - the IO-APIC-emulation: On 32-bit-systems this io-apic-emulation (needed for passing interrupts between CPUs) has to use a full software-context-switching - making things slow.
I tried recreating the problem with CentOS 5 64 Bit as VM, two CPUs: no problem With CentOS 5 32 Bit as VM: same problem.
I guess some problems with multi-cpu-VMs using 32-bit-operating-systems on a 64-bit hardware are related to this - no matter if you are using xen (fully virtualized), VirtualBox or VMWare.
Kind regards
Nils
-----Original Message----- From: centos-virt-bounces@centos.org [mailto:centos-virt-bounces@centos.org] On Behalf Of Akemi Yagi Sent: Monday, July 06, 2009 10:24 PM To: Discussion about the virtualization on CentOS Subject: Re: [CentOS-virt] High CPU usage when running a CentOS guest inVirtualBox
On Mon, Jul 6, 2009 at 10:22 AM, Sagi Basharisagi@boom.org.il wrote:
On my new box where I currently encounter the problem I tried installing the regular 2.6.18-92.1.22 kernel with the "divider=10 clocksource=acpi_pm" parameters like you suggested, and
also the old
kernel-vm package, and in both of these attempts idle host
CPU usage
was at 50%. So it looks like although the symptoms are the same the cause is different.
I guess it may be related to the newer version of VirtualHost, the different hardware or the different operating system. Any idea what else I can try to reduce the CPU usage on this host?
Because the issue is most likely related to VirtualBox and Windows rather than CentOS, you may have a better chance of getting help by going to the VB channels:
http://www.virtualbox.org/wiki/Community
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