Continued from opensuse-factory: > >>>> Probably other virtualization technology have the same issue, do > >>>> not use ntp. I do not know for certain. > >>> > >>> With xen, my guests run ntpd and have xen.independent_wallclock=1. > >> > >> And both host and guest try to adjust the speed of the mother board > >> hardware clock chip? (not the bios clock, that's a very different > >> one). > > > > No, only the Dom0 does that. The guests are independent when you > > use xen.independent_wallclock=1. > > >http://www.novell.com/documentation/vmserver/config_options/data/b9qzhq5.html > > But if you run the ntp daemon on guests, it tries to adjust the speed > of the clock there. That's how it works.
Of course, that's what you want it to do. You want the guest clock synchronized. It would appear to be a good idea to have ntp on the xen Dom0 govern the clock for all the guests, but in my experience systemd does not like that. I looked into in March 2015 when I was virtualising some systems, and found the Novell page above. The Xen FAQ: https://wiki.xen.org/wiki/Xen_FAQ_DomU also recommends running ntp in each DomU. Finally, Werner Flamme wrote: > When you install SAP systems on top of Xenified VMs, there is the > recommendation to do the latter: disable the sync and run a separate > ntpd in the DomU. This is also a recommendation for VMs inside a > VMWare environment - the problem ist the same there. Back in March last year I did ask what the typical practice was, but noone had any suggestions. -- Per Jessen, Zürich (25.2°C) http://www.dns24.ch/ - free dynamic DNS, made in Switzerland. -- To unsubscribe, e-mail: [email protected] To contact the owner, e-mail: [email protected]
