I am running CentOS 5.3 as a VirtualBox 3.0.0 guest running on Windows XP.
The Windows host CPU usage is constantly at 50% although the CentOS guest is completely idle (i.e. 0.00 load average).
I know this is a common problem related to the 1000Hz frequency that the CentOS kernel runs at, and previously a special kernel-vm packages were released to resolve the issue. However, these packages are out of date and the README says that they are not not necessary as of CentOS 5.3. I found out that there is supposedly a kernel parameter divider=10 that reduces the frequency to 100Hz with the standard kernel but it doesn't seem to have any effect when running inside VirtualBox.
Is there any way to resolve the issue without resorting to a custom kernel?
Best Answer
The proper syntax for the divider parameter is:
RHEL-5 32 bits: "divider=10 clocksource=acpi_pm"
RHEL-5 64 bits: "notsc divider=10"
Had you already tried these with this syntax or simply divider=10?