FreeBSD 7, runaway clock as guest OS on Microsoft Virtual Server

[Maxim Khitrov]

On Wed, Jan 21, 2009 at 2:41 PM, Jeffrey Williams <jeff at sailorfej.net> wrote:
> Hi Folks,
>
> I am trying to run FreeBSD 7 on Microsoft Virtual Server 2005 R2, Windows
> Server 2003, on a Dell 2950.
>
> I am having a problem with the system clock running excessively fast, I
> initially tried installing 7.1 release but received a nearly continuous
> stream of the "calcru: runtime went backward errors", I tried rolling back
> to 7.0, and it improved somewhat, but I still received regular "calcru"
> errors, and it the system clock was running to fast for ntpd to keep up with
> it, I set sysctl kern.timecounter.hardware to i8254 (it tries to default to
> ACPI-safe), which helped more, ntpd is now able to keep pace with it, but
> only barely, and I haven't seen any "calcru" errors yet.
>
> From the boot time dmesg, on the CPU line, the frequency reported with in
> the parenthesizes varies on almost every reboot.
>
> Are there any other adjustments I can make to get this under control?

Have you tried reducing the value of kern.hz (kern.hz="100" in
/boot/loader.conf)? That fixes some clock-related problems on VMWare
Server.

- Max