Per Jessen [19.03.2015 09:07]:
I have problem with domU clock. It lose 30 minutes each day. How can i synchronize it with dom0 clock?
Is this PV domU? If yes, setting /proc/sys/xen/independent_wallclock to 0 (the default) should make it sync with dom0. You only need ntp on dom0, and domUs will follow.
This is the setup I started out with, and where I see systemd reporting "Time has been changed" about once a minute.
OTOH, that same paragraph also says:
The alternative, set /proc/sys/xen/independent_wallclock to 1 and run ntp on domU.
Which is what I am doing now. No systemd messages.
Most confusing, to be honest.
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. It did not cause pain to set up one host as ntp server with "outer world" sources and the VMs as ntp clients listening to that host only, so I do not get headache while pondering which way to sync time :) Just my 2¢, Werner --