'Live' Migrate messes up NTP on FreeBSD domU - any suggestions?

Tue Jul 12 12:36:26 UTC 2016

Hello list,

I know this is old but I discovered the same problem and found this thread but no newer information.

--On Mon Nov 9 10:23:04 UTC 2015 Karl Pielorz <kpielorz_lst at tdx.co.uk> wrote:

> I've tested this on two pools now. The original production pool (Xeon 
> E3-1220 v3 @ 3.10GHz) has the issue.
> 
> Our office / test pool (Xeon L5630 @ 2.13Ghz) also -has the issue-. Both 
> are setup pretty much identical (same storage solution, both running 
> FreeBSD 10.1/10.2-R with 'xe-guest-utilities' installed). Running or not 
> running NTP doesn't make a difference.
> 
> Live migrates result in the domU gaining several seconds (thus breaking NTP 
> if it is running) else leaving the host 'running in the future' vs. both 
> external clocks, and NTP sync'd clocks on the xenserver.
> 
> As it's easily reproducible I guess I'll file it as a bug...

We run a XenServer 6.5 SP1 pool with all patches up to XS65ESP1033 on Fujitsu Primergy RX300 S6 servers. My test VM is FreeBSD 10.3 with xe-guest-utilities-6.2.0_2 and xen-guest-tools-4.6.1 installed.

After live migration the VM's clock is also several seconds in future.

I use "tinker panic 0" in /etc/ntp.conf as workaround. Then some minutes after the migration the time is in sync again.

Here is some output from a peerstats log:

... VM running on "old" host
57581 41601.319 172.30.99.31 965a 0.000911290 0.000156970 0.437525532 0.000079273
57581 41603.285 172.30.99.31 965a 0.000931010 0.000158095 0.187527895 0.000087612
... VM migrated to "new" host
57581 41675.500 172.30.99.31 965a -6.986332827 0.000539032 0.062950133 6.987199663
57581 41744.489 172.30.99.31 905a -6.984444823 0.000480657 0.000739123 6.467141976
57581 41811.509 172.30.99.31 905a -6.982751485 0.000298934 0.000864689 5.902246019
57581 41879.519 172.30.99.31 905a -6.980983259 0.000466260 0.000933010 5.277805891
57581 41945.518 172.30.99.31 905a -6.979267346 0.000409787 0.000950354 4.569599170
57581 42014.502 172.30.99.31 905a -6.977464766 0.000497814 0.000979475 3.730107446
57581 42080.531 172.30.99.31 905a -6.975764545 0.000413500 0.000969749 2.636950596
57581 42148.485 172.30.99.31 905a -6.973984885 0.000336825 0.000977892 0.007845778
57581 42211.541 172.30.99.31 9024 0.036648577 0.000355228 7.937500599 0.000000238
57581 42213.518 172.30.99.31 963a 0.037403812 0.000173852 3.937508397 0.000755235
... VM still running on the "new" host, now synced

Regards,

Christian