RE: Ubuntu in bhyve

From: <>
Date: Thu, 15 Jun 2023 21:42:35 UTC
Make sure your guests (and host) are syncing to a reliable time source. I
have heard time to time of some having this issue, but we haven't seen it
though we do use OpenNTPD across our BSD/*nix guests (windows has its own
time sync service).






<> On Behalf Of Sean McBride
Sent: Friday, June 16, 2023 5:20 AM
Subject: Ubuntu in bhyve


Hi all,

I am running bhyve (via TrueNAS Core 13) and have some Ubuntu 20.04 and
22.04 guests.

One of them rather regularly seizes up hard, where I cannot ssh to it, then
after a few minutes works again. This happens repeatedly and on and off. In
the Ubuntu logs I see messages like:

clocksource: timekeeping watchdog on CPU2: Marking clocksource 'tsc' as
unstable because the skew is too large:
clocksource:                       'hpet' wd_nsec: 536417782 wd_now:
638cb3ff wd_last: 63036152 mask: ffffffff
clocksource:                       'tsc' cs_nsec: 536821277 cs_now:
225a9f9e1250b cs_last: 225a9b3891749 mask: ffffffffffffffff
clocksource:                       'tsc' is current clocksource.
tsc: Marking TSC unstable due to clocksource watchdog
TSC found unstable after boot, most likely due to broken BIOS. Use
sched_clock: Marking unstable (12899572906362, 9192186981)<-(12908811630850,
clocksource: Checking clocksource tsc synchronization from CPU 2 to CPUs
clocksource: Switched to clocksource hpet
loop8: detected capacity change from 0 to 114000

Although I don't fully grok these messages, they sound like something that
could be bhyve's fault. Anyone know if that may indeed be the case?

There is a thread about this on the TrueNAS forum too, but with no answers