[CentOS-virt] VMware Server clock woes (running too fast)

Akemi Yagi amyagi at gmail.com
Wed Aug 20 01:07:58 UTC 2008

On Tue, Aug 19, 2008 at 5:55 PM, Michael Ekstrand <michael at elehack.net> wrote:
> I'm running VMware Server 1.0.6 on a CentOS 5.2 host and am having some
> clock difficulties.
> Host OS is x86_64 running on 1.9 GHz AMD Sempron, nVidia chipset.
> Guest OS's are 32-bit FreeBSD (clock works fine after disabling ACPI,
> setting the clock source to the PIT, and running the guest tools), WinXP
> (unknown clock status), and i686 CentOS 5.2 (here is the problem).
> I've tried pretty much everything to try to fix it.  I have host.cpukHz,
> host.noTSC, and ptsc.noTSC set in /etc/vmware/config.  I've booted my
> kernel with noapic, nosmp, noacpi, divider=10.  Sadly, I hit the
> clocksource=pit with divider bug, so I have not been able to boot with
> both that and divider=10, although clocksource=pit without a divider
> also does not work.  I even built a custom kernel with SMP and APIC
> disabled, CPU_HZ=100, and booted with clocksource=pit noacpi, and it
> also gains time.
> Could anyone provide a recommendation as to what I can do to fix this problem?

I understand you built a 100Hz kernel, but *just in case*, you might
want to try CentOS-supplied 100Hz kernel (kernel-vm) available from:


Also, enable time sync with host if that has not been done.


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