Re: [Bug 212265] New: clock_gettime(CLOCK_TAI, ...) should return an error when TAI has not been configured

From: Richard Cochran
Date: Mon Mar 29 2021 - 10:22:41 EST


On Mon, Mar 29, 2021 at 11:16:48AM +0200, Miroslav Lichvar wrote:
> On Fri, Mar 26, 2021 at 08:28:59PM -0700, Richard Cochran wrote:
> > Using ntpd on Debian, the service will set the offset, but only after
> > synchronization with the upstream server has been established, and
> > this takes about five minutes, IIRC.
>
> With the iburst option it shouldn't take more than 10 seconds. There
> might be an issue wrt stepping the clock when the initial offset is
> large.

Really? Debian has

# pool.ntp.org maps to about 1000 low-stratum NTP servers. Your server will
# pick a different set every time it starts up. Please consider joining the
# pool: <http://www.pool.ntp.org/join.html>
pool 0.debian.pool.ntp.org iburst
pool 1.debian.pool.ntp.org iburst
pool 2.debian.pool.ntp.org iburst
pool 3.debian.pool.ntp.org iburst

I guess I'll measure again, but I'm pretty sure it took a long time to
get to TAI being set.

> In Fedora and derived distros using chrony by default the
> TAI-UTC offset should be set right on the first update of the clock as
> expected.

(Maybe it is time to switch to chrony ;)

Thanks,
Richard