I ran two instances of Debian Etch 4.0 on VirtualBox 1.3.8.
I installed the VirtualBox addons and I had a CPU Load of around 1% in idle mode for each machine.
Now I upgraded to 1.5.2 (and reinstalled VirtualBox addons of course) but now I get a load of around 30%-50% for each instance.
I run Centos5 2.6.18-8.el5 SMP Kernel on the Host.
I tried nohz=off in the boot options but no change.
There is also an issue with multi core and smp. I have seen 100% CPU load on my dual core Desktop. Running the same VM on my (older) single core Laptop I had a normal CPU load between 1% and 10%.
I have read a suggestion anywhere here to compile a new kernel without smp... (no comment)
The point is, that I still use the same host machine with the same kernel and the same virtual machines. There was even no difference with old (1.3.8 ) vbox extension and updated vbox additions.
So 1.3.8 was o.k. in terms of performance, 1.5.2 is not.
Do you have any idea which version between 1.3.8 and 1.5.2 may perform better?
I've seen it in version 1.5.0 and in version 1.5.2. Other versions I don't know about this behavior. It is one of these bugs I use a workaround and wait until it is fixed.
As I said I don't know much about this issue. But it's the question if the host or the guest should run without smp. If it's the guest it doesn't make any difference because VirtualBox doesn't support smp for guests till this day. Mabye you can have a look with the search function on this site.
Or is there someone else out there who knows a little bit more about this?
Just made a short try. Installing CentOS 5 x86_64 + Virtual Box 1.5. Than installing on top Centos x86_32. During installation one core get up to 100% but not during normal use. (The machine is HP ML350 QC). So I can't confirm that issue in the moment.
I saw that someone somewhere adviced in a post to set the machine type to "unknown" in the GUI. This improved the load used by a Win2K guest.
But my Debian 4.,0 etch clients still consume about 40% each.
When will a new release with a fix be evailable? Or in other words: When can 1.5.3 be expected?