[ntp:questions] Wrong time after changing hardware

Steve Kostecke kostecke at ntp.org
Tue Jul 24 03:02:47 UTC 2007

On 2007-07-23, David L. Mills <mills at udel.edu> wrote:

> The Linux style to provide an initial frequency file with ASCII 
> zero content completely defeats the rapid initial frequency calculation. 

There is no one Linux OS. There are, however, many OSes which are built
on the Linux Kernel. These OSes differentiate themselves in various ways
such as in their choice of package/software management systems, library
versions, included software, supported architectures, and so on.

Choices about details such as the pre-seeding of an initial frequency
file are made at the individual OS level, not the kernel level. So the
inclusion of an invalid drift.file can not correctly be described as a
"Linux Problem."

> At first startup of a virgin system, the location of the file should be 
> specified, but the file itself should not exist.

While it is not possible for me to comment meaningfully on every single
OS using a Linux kernel, here are my notes on a few of them:

The pre-packaged binary version of the NTP Reference Implementation
shipped in the current stable release of Debian (the OS I use)
does not include a drift file. Further, neither the installation
support scripts nor the ntpd init script pre-create the drift file.
The list of files in the i386 version of this Debian package is at
http://packages.debian.org/cgi-bin/search_contents.pl?searchmode=filelist&word=ntp&version=stable&arch=i386 and this package may be downloaded
from http://packages.debian.org/ntp

The pre-packaged binary version of the NTP Reference Implementation
shipped with CentOS 5 (e.g.
./pub/centos/5/os/i386/CentOS/ntp-4.2.2p1-5.el5.i386.rpm) does not
appear to include or install a drift file.

The source version of the NTP Reference Implementation shipped with
Gentoo (e.g.
http://sources.gentoo.org/viewcvs.py/gentoo-x86/net-misc/ntp/) does not
appear to include a drift file.

There are a number of OSes which are based on Debian or RedHat and
likely follow their parent OS'es packaging policies.

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

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