[CentOS-virt] Fast clock under VMWare

Elliot Lee elliot at vmware.com
Fri Feb 22 18:10:17 UTC 2008

On 2/22/08 9:20 AM, "Ray Van Dolson" <rvandolson at esri.com> wrote:

> I think the typical fix for the clock-too-fast problem is to boot your
> guest OS with the clock=pit option and then use the VMware Tools time
> synchronization option.
> If the clock is running too slow is where you want to look into using
> one of the 100Hz kernels.
> See:
> http://kb.vmware.com/selfservice/microsites/search.do?cmd=displayKC&externalId
> =1420

So the time sync option is meant to correct gross clock mismatches, but it's
not intended to fix ongoing clock drift. If there's clock drift going on,
it's probably another problem. Can you double-check that 'cat
/sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq' outputs the same
number as your 'cpuKHZ' setting in your config.ini file? Have you also tried
make sure that the CPU speed is locked to a constant speed? (See
playKC&externalId=708 for help doing the latter - although it sounds like
you may have already played around in our BIOS a little.)

Hope this helps,
-- Elliot

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