Clock lagging behind on FreeBSD 9.0-RELEASE under KVM

Martin Dimitrov martin.dimitrov at
Tue Jun 5 15:17:03 UTC 2012


I am new to FreeBSD, decided to migrate a web server to FreeBSD. I
recently both a VPS that claim to use KVM as a virtualization service, I
don't know the details of the real hardware running behind nor what is
KVM running on. Anyway I have an issue with clock on my FreeBSD
installation that I can't live with. The clock is lagging behind, for
example running sleep 30 is really sleeping around 35 seconds not 30.
Also seems that NTP is not able to manage with this drift in time.
Before posting here I red about similar problems mostly related to
VMWare guests, but the solutions suggested are following:

set kern.hz=100 or kern.hz=50 (doesn't work for me)
set hint.apic.0.disabled=1 (this makes the guest hangs while booting
also it discarding the SMP capabilities of the kernel which I assume is
not a good idea)
set kern.timecounter.hardware TSC (doesn't work for me)

Is there any chance I deal with this time drifting issue somehow? If
somebody faced such issue and managed it I would be happy to try another
possible solution?
Alternatively I can switch the provider with other that is using Xen for
virtualization, I guess is better, but no guarantee that would not have
the same issue. :(


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