From: Andreas Kinzler <hfp@posteo.de>
To: xen-devel@lists.xenproject.org, Paul Durrant <Paul.Durrant@citrix.com>
Subject: [Xen-devel] wall clock drift on C24x mainboard, best practices
Date: Sat, 12 Oct 2019 20:47:19 +0200 [thread overview]
Message-ID: <4bc44777-103b-ada5-839a-809da33ba00c@posteo.de> (raw)
Hello all, hello Paul,
On a certain new mainboard with chipset C242 and Intel Xeon E-2136 I
notice a severe clock drift. This is from dom0:
# uptime
20:13:52 up 81 days, 1:41, 1 user, load average: 0.00, 0.00, 0.00
# hwclock
2019-10-12 20:27:37.204966+02:00
# date
Sat Oct 12 20:07:19 CEST 2019
Kernel is 4.13.16 vanilla, Xen 4.10.2
So after 81 days uptime there is a difference of over 20 minutes between
"date" and "hwclock". I operate many Xen servers and have never seen
such a great drift except on this type of mainboard. What could be the
reason?
In general, what is the current best practice for NTP sync? Run it in
dom0? In domU? Both? How does the domU type (Linux HVM/PVM/PVH or
Windows HVM with WinPV drivers) make a difference?
Regards Andreas
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next reply other threads:[~2019-10-12 18:47 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-12 18:47 Andreas Kinzler [this message]
2019-11-13 23:10 ` [Xen-devel] wall clock drift on Coffee Lake / C24x mainboard (HPET broken?), best practices Andreas Kinzler
2019-11-14 11:29 ` Jan Beulich
2019-11-15 11:01 ` Andreas Kinzler
2019-11-18 19:35 ` Andreas Kinzler
2019-11-19 9:29 ` Jan Beulich
2019-11-19 14:31 ` Andreas Kinzler
2019-11-19 14:44 ` Jan Beulich
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