Proposed release goal for Squeeze: Switch to dependency based boot sequencing

[Henrique de Moraes Holschuh]

On Fri, 17 Apr 2009, Michael Biebl wrote:
> Henrique de Moraes Holschuh wrote:
> > On Fri, 17 Apr 2009, Michael Biebl wrote:
> >> I think, one missing piece is a proper interface for updating init
> >> script priorities (if the depencies or the list of runlevel changes) in
> >> a policy compliant way.
> > 
> > There is no such interface in this case (if we had one, insserv would have
> > to make it a no-op).  You have to edit the initscript metadata directly
> > (because it is embedded in comment headers on the initscript itself) to do
> > such changes, then tell the system to rebuild the initscript dependency
> > tree.
> 
> How do you do that exactly while preserving local modifications?

The local modifications have to be done on the initscript headers, which are
conffiles since the dawn of time.  The user is warned that by switching to a
dependency-based initscript system, the old order information is deemed
irrelevant and thus completely ignored.

There is also an override directory that can be used to change the
dependency headers instead of editing the initscript, but we should get rid
of any need to ship files in there as part of the release goal (local admin
can place stuff there as he wishes).

So, you can have local modifications to the *DEPENDENCY* information in an
override directory.

> Do you propose maintainer scripts should add special case code for insserv?

I don't think that would be needed.  During a dpkg run, a single insserv run
at the end of the dpkg run should be scheduled (if insserv is active) via
the dpkg triggers and also by any calls to update-rc.d (which will just
schedule the insserv run, really), as well as changes to /etc/init.d/* and
the insserv override directories.

Nobody said anything about getting rid of non-dependency-based boot for
Squeeze, BTW.  We should aim to make dependency-based (and if at all
possible, parallel execution) perfect, and the default... but not the only
option, at least not yet.  Maybe for squeeze+1 or squeeze+2.

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh