Jan Beulich wrote: >>>> On 24.11.16 at 13:51, <[email protected]> wrote: >> Jan Beulich wrote: >> >>>>>> On 22.11.16 at 07:50, <[email protected]> wrote: >>>> i just installed our first Leap 42.2 DomU and as i wanted to adapt >>>> our usual scriptset i noticed, that the settings for independent >>>> wallclock seem to be missing. >>>> While the doc is stating that independent wallclock settings should >>>> apply for Leap 42.2, /proc/sys/xen is not showing the appropriate >>>> file. >>>> >>>> /proc/sys/xen # ls >>>> balloon >>>> >>>> Has something gone wrong during installation, or is the >>>> documentation faulty? >>> >>> I don't think the pv-ops kernel has ever supported the concept of >>> independent wallclock as configurable behavior. If you observe any >>> misbehavior without it, please open a bug. >> >> We started switching to independent wallclock when systemd was >> introduced - systemd kept complaining about the clock being adjusted >> or something like that. > > Over time we had kernel problems in that area, so much would > depend on when exactly you found it necessary to switch.
Judging by my mailing list postings, I think we started in March 2015. https://lists.opensuse.org/opensuse-virtual/2015-03/msg00020.html > Also I don't think your reply really demonstrates any observed > misbehavior with the pv-ops kernel, yet that's the only criteria > based upon which fixing that kernel or considering to re-introduce > that control would become possible routes forward. We observed ntp-related poor behaviour by systemd, that's all. Hundreds of message being written about "Time has been changed". Switching to local ntp and independent wallclock solved the issue. >> After a lot of research, we switched to using >> independent_wallclock for all guests. Afair, this was/is also the >> SUSE/Novell recommendation. > > Not as far as I know. As long as there are no bugs, running e.g. NTP > once in Dom0 would seem the more efficient model compared to > running it in every DomU. But of course I don't know who gave this > recommendation, and in which context that was. http://www.novell.com/documentation/vmserver/config_options/data/b9qzhq5.html https://doc.opensuse.org/documentation/leap/virtualization/html/book.virt/sec.kvm.managing.clock.html "To effectively use an external time source, such as NTP, for time synchronization on a virtual machine, the virtual machine's independent wallclock setting must be enabled (set to 1)." Perhaps not a recommendation, but given that systemd didn't like the domU just relying on the Dom0 clock, using running ntp in the DomU and enabling independent wallclock was a solution. https://wiki.debian.org/Xen/Clocksource https://lists.opensuse.org/opensuse-virtual/2015-03/msg00022.html I remember finding it very difficult to get any solid information on this topic. -- Per Jessen, Zürich (9.9°C) -- To unsubscribe, e-mail: [email protected] To contact the owner, e-mail: [email protected]
