I want to add some information When the "50 minute shift" occurs. It occurs simultaneously on all domU and dom0. on all domU and dom0, the syslog says Clocksource tsc unstable (delta = -2999660303146 ns) (or something very near 3000 seconds) Using ntp is ok to resync the clock but does not prevent the problem from occuring.
about bug 674907 "shifts the clock by 50 minutes unexplicably under a Xen dom0" I think this problem is definitely grave and nearly critical. Time is one of the most important things on the operating system. The bug seems to be kernel related and I'm not skilled enough to solve the problem myself but I can't wait for it to be solved. So, I wrote a dirty workaround. Check timestamp every 10ms and if it has shifted more than 300 seconds, put back the old value. I know this is horrible but I have no choice. -------------- next part -------------- A non-text attachment was scrubbed... Name: chktime.c Type: text/x-csrc Size: 1539 bytes Desc: not available URL: <http://lists.alioth.debian.org/pipermail/pkg-xen-devel/attachments/20121001/573bc9bb/attachment.c>
On Mon, Oct 01, 2012 at 10:32:36AM +0200, Pierre Colombier wrote:> When the "50 minute shift" occurs. It occurs simultaneously on all domU > and dom0. > on all domU and dom0, the syslog says > Clocksource tsc unstable (delta = -2999660303146 ns) (or something very > near 3000 seconds)The TSC is unstable for whatever reason. Please provide complete kernel (dmesg) and hypervisor logs (xm dmesg). Please check if the machines runs the latest firmware. Does it also happen with the testing versions of either Xen or Linux? Bastian -- To live is always desirable. -- Eleen the Capellan, "Friday's Child", stardate 3498.9