Mailinglist Archive: opensuse (1002 mails)

< Previous Next >
Re: [opensuse] chrony and hwclock
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 2011-07-16 13:31, Per Jessen wrote:
Carlos E. R. wrote:

On 2011-07-16 09:28, Per Jessen wrote:
Carlos E. R. wrote:


Both clocks have different drifts, taken into account differently.
#1 by hwclock, #2 by ntp. Don't mix names!

man ntp.conf:

driftfile
This command specifies the complete path and name of the file
used to record the frequency of the local clock oscillator.

That's right, the drift of the system clock.


Wait - how did you make "local clock oscillator" = system clock? The
local clock oscillator is a bit of hardware essentially producing a PPS
signal for advancing the hardware clock. The hardware oscillator has a
instability or drift, i.e. it is slightly inaccurate. ntp uses the
drift-information to fake a PPS when an external source is not
available. ntp calls adjtime() to adjust the system clock (software)
in tiny steps.

You are confusing the available clocks.

Again. The hardware clock is a cmos chip running of small battery or the
psu when available. It does not produce any pulse. It's drift is not
adjusted by ntp.

What ntp does when there is no external accurate source is a loopback to
the system clock, by another name.



That is not the drift file I'm talking about - I'm talking about NTPs
drift file, usually /var/lib/ntp/drift/ntp.drift.

That's the drift of the system clock. The file I'm talking is for the
hardware clock. You are confusing both.

- --
Cheers / Saludos,

Carlos E. R.
(from 11.4 x86_64 "Celadon" at Telcontar)
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.16 (GNU/Linux)
Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org/

iEYEARECAAYFAk4hi+kACgkQtTMYHG2NR9UuZgCglhR+hhaseuQL3OwYgA71yBRh
3eYAniXln0YA1XXXcNFkbpaRxWOTMGdk
=j9sq
-----END PGP SIGNATURE-----
--
To unsubscribe, e-mail: opensuse+unsubscribe@xxxxxxxxxxxx
For additional commands, e-mail: opensuse+help@xxxxxxxxxxxx

< Previous Next >
This Thread