[ntp:questions] Cluster NTP configuration

Steve Kostecke kostecke at ntp.org
Mon Jun 20 20:06:11 UTC 2011

On 2011-06-20, Steve Tryon <x77ssiwdo at yahoo.com> wrote:

> Synchronization to a tenth of a second is fine for my purposes.

So +/- 0.05 sec (50ms) is OK? ntpd should have no problem with that.

>  All servers will be running RH 5.5.

Keep in mind that the version of NTP shipping with that OS is probably
very old.

> My concern is centered around a bad local clock.  If I lose my
> external connections, will a bad hardware clock start to cause large
> incremental corrections?

ntpd does not use the RTC on the motherboard. Not even when "synced" to
the Undisciplined Local Clock (127.127.1.x) aka "LOCAL".

When ntpd is "synced" to "LOCAL" it just accepts the kernel's notion of
the correct time. So when the kernel clock drifts ntpd will follow.

Steve Kostecke <kostecke at ntp.org>
NTP Public Services Project - http://support.ntp.org/

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