On Mon, Jun 23, 2014 at 12:28:53PM +0100, David Woolley wrote: > On 23/06/14 12:03, Rob Heemskerk wrote: > >Could we say it is safe to run ntp servers on a virtualized platform or do > >we still need a few (4?) dedicated pieces of hardware to run our internal > >NTP servers? > > No. > > Normal virtualised machines are not intended for hard realtime applications. > Also, the host clock can and should be disciplined using NTP, so there is a > risk double correction.
I think it all depends on the VM implementation and what clocksource is used in the guest. If the guest is using tsc (i.e. its frequency is independent of the host clock), it will need to run its own NTP client. If the guest's clock is locked to the host's system clock, there still may be a static offset between them and an NTP client (possibly using the host as the NTP server) can be used to correct the offset. -- Miroslav Lichvar _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
