On Mon, Nov 30, 2009 at 12:14 PM, Thomas Harold <thomas-lists at nybeta.com> wrote: > On 11/30/2009 11:34 AM, Jonathan Garden wrote: >> This is really stupid question. But referring to: >> http://lists.centos.org/pipermail/centos/2009-October/083791.html >> I don't see any line related to ntpd in my /var/log/messages . Do I need >> to turn-on ntpd for timekeeping on VMs? Some people say not to use ntpd >> on VMs for timekeeping or is it ntpdate cron job? Can someone please >> elaborate on this? > > On Xen guests, unless /proc/sys/xen/independent_wallclock is set to 1, > the DomU will slave itself to the Dom0 clock. So you probably don't > need NTP inside the DomU. Our Dom0 uses ntpd to keep itself > synchronized with the internal time servers on our LAN. > > Whether that is better then using ntpd combined with setting that flag > to zero... I'm not sure. The OP link is talking about VMware guests, not Xen. You can't apply knowledge from one to the other.