time drift

[D Hill]

On Thu, 15 May 2008 at 14:16 -0700, ccowart at rescomp.berkeley.edu confabulated:

> David Kelly wrote:
>> Its PC commodity-grade. Not all that unusual even for stuff sold
>> claiming to be a "server". This is in no small part why ntpd exists.
>>
>> nptd calculates a correction coefficient and (under FreeBSD) stores it
>> in /var/db/ntpd.drift for use on next start so as to more quickly
>> establish a lock.
>>
>> So in short ntpd calibrates your clock in order to minimize the
>> corrections required. Is The Right Thing To Do.
>
> We run a large number of FreeBSD servers under vmware. We've seen ntpd
> silently die, because the drift becomes "insane." What do others do in
> this situation? (We've resorted to croning ntpdate for VMs.)

I've also found running FreeBSD 6.2, 6.1 and 6.0 in VMWare, I've had to 
reduce kern.hz in /boot/loader.conf. I had to reduce it to 50. Otherwise 
the clock really lost time.