[CentOS] clock sync/drift

[Craig White]

On Jan 22, 2013, at 8:16 PM, Matt Garman wrote:

> Hi,
> 
> We have a little over 100 servers, almost all running CentOS 5.7.
> Virtually all are Dell servers, generally a mix of 1950s, R610s, and
> R410s.
> 
> We use NTP and/or PTP to sync their clocks.  One phenomenon we've
> noticed is that (1) on reboot, the clocks are all greatly out of sync,
> and (2) if the PTP or NTP process is stopped, the clocks start
> drifting very quickly.
> 
> If it was isolated to one or two servers, I'd dismiss the issue.  I
> also had this problem under CentOS 4.
> 
> I suspect something is mis-configured, because I can't imagine the
> hardware clock on ALL these servers is *that* bad.
> 
> Anyone else dealt with anything similar?
----
pretty much everyone deals with this issue in one way or another.

You don't actually show us your ntp.conf but generally, I would recommend that you make this the very first line of ntp.conf:
tinker panic 0

Craig