[ubuntu-za] Ubuntu 7.10 on VM : Serious clock instability

[Simon Hoffe]

Hi All,

I've got a serious problem with clock stability on an Ubuntu 7.10
server running in VM on a VMWare ESX platform.

At some random time, on some nights, the date will jump years backwards.

What happened when I logged in this morning:

Last login: Thu Feb 21 13:04:53 2008 from workstation
user at server:~$ date
Wed Jul 16 21:05:11 SAST 1986

I'd seen this previously and I installed ntpd and configured it to
pull time for a nearby server. This problem has now manifested with
and without ntpd installed! At the same time as I installed ntpd I
also installed and configured the VMWare toolset, which also appears
to have made no difference.

ntpd doesn't like correcting a date when it's so far out (I think
there's an option to override this behaviour - but that's not the root
cause).

I've got the following in /var/log/messages:

Feb 21 18:17:25 server -- MARK --
Feb 21 18:37:25 server -- MARK --
Jul 16 21:14:13 server kernel: [296710.149028] Clocksource tsc
unstable (delta = 1133957718661 ns)

Any ideas?

Is there a known issue running Ubuntu 7.10 on a VM?

Ubuntu installation is fully up-to-date

The server has now gone unstable, my ssh session has hung and I can't
even log in at tty1. I'm going to have to do a hard reset...

Many thanks,
Simon

--
Simon Hoffe
sjhoffe at gmail.com
Cell: +27 82 869 7441
Tel (work): +27 31 508 2884
Fax (work): +27 31 539 5255