On Thu, Jul 18, 2013 at 03:15:12PM +0800, Thomas Goirand wrote:
> On 07/18/2013 01:29 AM, Steve Langasek wrote:
> > - Reliable, low-maintenance system startup (no races / ordering bugs)
> Could you point at these bugs?
No.
Look, Thomas, you asked what the goals of event-based init systems are, and
I thought that was a fair question to answer from the upstart POV because
there are many Debian developers who have never used Ubuntu in production
and so don't have an appreciation of the scope of the problems that upstart
addresses. But I'm not going to go point-by-point with you arguing about
how OpenRC fails in addressing these points, because that's a waste of your
time and mine. It's not going to change the fact that OpenRC *doesn't*
address these fundamental problems with sysvinit and isn't a modern init
option.
But unless you've only ever used Debian on systems with a flat
partition:filesystem structure, with no network filesystem mounts, no
LVM/RAID/LUKS, and no networks more complicated than a single interface,
you've either been affected by these race conditions, or you've been relying
on the chewing-gum-and-baling-wire workarounds that Debian has in place to
paper over these races. The problems are pervasive and systemic, and have
become progressively more severe over time as hardware becomes faster. An
init system that has not *fundamentally* addressed this class of problem
with its design is not bringing anything interesting to the table.
> > - Fast startup
> I thought everyone claimed (including systemd supporters) that this was
> a "teenager side effect" which we didn't care much about.
http://blip.tv/ubuntu-developers/ubuntu-uds-q-tuesday-pm-google-ubuntu-derivatives-and-community-6188491
3:07: "a reboot costs [Google] a million dollars".
The people who have dismissed boot speed as a matter for toy systems are
being naive. It is not the number one priority for upstart or for anyone
else; but downtime costs money, just as inefficient power control on systems
costs money; and time spent booting is downtime. Time spent improving the
boot speed for the millions of systems that run Debian is time well spent.
> > My understanding is that OpenRC only addresses the last of these points, and
> > adds nothing over sysv-rc for the rest.
> I don't agree with this view, and I believe that indeed, you
> miss-understood. This wiki page (which has been posted here before)
> doesn't agree with your view either:
> http://wiki.gentoo.org/wiki/Talk:Comparison_of_init_systems
I got as far as this:
sysvinit Upstart systemd OpenRC SMF
[...]
Device-based Activation no no[4] yes ?? ??
... and stopped reading. Not only does it reproduce Lennart's deceptive
claim that Upstart doesn't support device-based activation without bothering
to include the footnote, but the author of this page doesn't even *know* if
OpenRC supports it? This is such a fundamental gap it's not even funny.
--
Steve Langasek Give me a lever long enough and a Free OS
Debian Developer to set it on, and I can move the world.
Ubuntu Developer http://www.debian.org/
slangasek@ubuntu.com vorlon@debian.org
Attachment:
signature.asc
Description: Digital signature