[ntp:questions] Flash 400 on all peers; can't get ntpd to be happy

Dave Hart hart at ntp.org
Wed Mar 9 20:46:53 UTC 2011

On Wed, Mar 9, 2011 at 20:24 UTC, Chuck Swiger <cswiger at mac.com> wrote:
> Because of the above, I've drawn the conclusion that "running ntpd's in the
> other DomUs/guest VMs is almost entirely pointless".

One oft-quoted reason I hear is "we don't control the Dom0" whether
it's corporate orgchart separation, or leased VMs.  The VMware
suggestion to run ntpd is an admission of engineering defeat.

While lurking on a conference call run by irc.freenode.net #freeswitch
people, someone mentioned maximizing the use of sub-$1000 16-core
servers drawing less than 2W with colo loss-leader offers for 100Mbit
connectivity and 2W power for less than $250/mo.  The speaker was
turning those into a dozen or more Windows Server VMs each leased to a
different customer and mentioned the Microsoft VM solution didn't have
problems with time in VMs, they get it from the supervisor (akin to
Dom0).  I'm sure programs can detect virtualization, but the point is
VoIP softswitches do care about latency and probably about system
clock jitter, another example alongside the lvm approach demonstrating
VM timekeeping can be respectable, it's all about the particular
virtualization software and its integration with guest OSes.

Dave Hart

More information about the questions mailing list