A bit more background info:
We've installed a webserver system that is a plain AMD system with 4Gb memory and a 3ware controller. It needs to run one production webserver for some basic hosting. But in order to restore and keep a bit of security, we've installed VMWare server on the host on top a CentOS Linux and installed the webserver in a i386 linux guest VM.
If we powerup the VM guest, kernel usage raises sometimes to 200% (= both cores fully loaded of the host CPU). Inside the guest VM's, cpu usage is 0%, runs actually idle.
On the host, Load averages range from 1.4 to 1.6 when the guest is running. No swap is in use and 1,5Gb memory is free. I also tried to install a second VM for some testing (basic OS, nothing else). This gives the same problem.
Output of the top command shows it are always the vmware-vmx processes of the guests that take all %sys usage (= kernel) of the host. Powering down the guest leaves the host in idle state with 0% cpu usage. For more info, refer to the screenshot in attach.
Could this be a flaw in the compiled modules VMware uses?
Host OS: CentOS 5.5 x86_64
Host Architecture: AMD dual Core 4400+ / 4Gb DDR2
Host Installed storage: 3ware 9650SE-2LP - Hardware RAID 1 (2x 250Gb disks)
Software: VMware Server 1.0.4., rpm, i386 installed
Kernel: vanilla CentOS kernel-2.6.18-53.el5.x86_6
Used guest OS'es: CentOS 5.5 i386 & Centos x86_64