Re: recommended clock source

Dor Laor
2009-08-03T07:04:50Z

On 08/03/2009 04:52 AM, Kent Tong wrote:
> Hi,
>
> It seems to be an unsettled issue, but, would any kind soul suggest the current
> best practice for setting the clock in Ubuntu Linux and Windows guests?

For Linux the best source clock is the kvm pv clock (exist from 2.6.27
and above).

For windows, standard acpi HAL uses the rtc clock by default. As long as
you use the -rtc-td-hack it won't drift.

When the tsc is not stable on the host or the host cpu might get into
deep sleep state (c2), you better use another source clock in the guest
- for windows it should be the pmtimer (using the boot.ini).

>
> Thanks!