Re: Question: Timekeeping between Host and Guest with NTP

2012-08-27 Thread Aritoki TAKADA
Hello, (2012/08/25 0:00), Marcelo Tosatti wrote: kvmclock driver has access to the ntpd corrected frequency of the host, but: 1) kvmclock time as reported to the guest uses the TSC as an offset in addition to the host monotonic clock, TSC is susceptible to frequency variations. The guest has

Re: Question: Timekeeping between Host and Guest with NTP

2012-08-24 Thread Marcelo Tosatti
On Fri, Aug 24, 2012 at 08:43:49PM +0900, Aritoki TAKADA wrote: > Thank you for your comment, > > (2012/08/24 3:13), Marcelo Tosatti wrote: > > >NTP should be running in the guest so as to synchronize the guest > >time-of-day clocks to UTC. > > > >kvmclock exposes the monotonic clock from the hos

Re: Question: Timekeeping between Host and Guest with NTP

2012-08-24 Thread Aritoki TAKADA
Thank you for your comment, (2012/08/24 3:13), Marcelo Tosatti wrote: NTP should be running in the guest so as to synchronize the guest time-of-day clocks to UTC. kvmclock exposes the monotonic clock from the host. The frequency of the host monotonic clock is corrected by host ntpd. This is pr

Re: Question: Timekeeping between Host and Guest with NTP

2012-08-23 Thread Marcelo Tosatti
On Wed, Aug 22, 2012 at 05:46:52PM +0900, Aritoki TAKADA wrote: > Hello, > > I'm planning to configure timekeeping between KVM host and guest, > but I'm confused by different suggestions. > The point is whether NTP should be working on guest or not. > > Here are the suggestions I found. > > Re

Question: Timekeeping between Host and Guest with NTP

2012-08-22 Thread Aritoki TAKADA
Hello, I'm planning to configure timekeeping between KVM host and guest, but I'm confused by different suggestions. The point is whether NTP should be working on guest or not. Here are the suggestions I found. Red Hat document: http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/h