On 2016-09-02 16:00, Per Jessen wrote:
Continued from opensuse-factory:
(by the way, this was https://bugzilla.novell.com/show_bug.cgi?id=773323)
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.
Yes, we want the clock synchronized, but not by adjusting the speed on guests. Just copied from the host. It adds load on the virtualized hardware. I know that vmware does recommends not running ntpd in guests, but instead use: tools.syncTime = "TRUE" I'll try again to find a source for this.
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.
This is against what I read the vmware people say. -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)