Re: s6 talk at FOSDEM 2017

From: Colin Booth <>
Date: Thu, 5 Jan 2017 21:33:41 -0800

On Thu, Jan 5, 2017 at 2:59 AM, Laurent Bercot
<> wrote:
> I didn't look too hard at the source code because things like this
> _should_ be documented no matter what. I remember early experiments
> with old RedHats or Debians where the gettys were actually started in
> parallel, but things may have changed since. My experience with Alpine
> matches yours: at least getty1 gets started after "openrc default" - but
> that's a busybox init implementation choice.

As I have learned with Debian, init waits until each line is done
before going on to the next. So in the case of boot it runs all the
"get to runlevel 2" stuff (aka, everything in /etc/rc2.d) before
moving on to launching gettys. I know this because ntpd has a really
lame behavior of taking a lock file per network interface, and on
hosts with 40 or 50 network devices it ends up stomping on itself for
about ten minutes. On those hosts, sshd is up significantly before the
serial console has a getty attached to it. The gettys and supervisors
are started in parallel with each other (or, more specifically in
series but fast enough to be effectively in parallel), but only after
the runlevel scripts have all completed.


"If the doors of perception were cleansed every thing would appear to
man as it is, infinite. For man has closed himself up, till he sees
all things thru' narrow chinks of his cavern."
  --  William Blake
Received on Fri Jan 06 2017 - 05:33:41 UTC

This archive was generated by hypermail 2.3.0 : Sun May 09 2021 - 19:44:19 UTC