Subject: Re: Thanks NetBSD [Was Re: Debian redefines itself]
To: Douglas Allan Tutty <dtutty@porchlight.ca>
From: Steven M. Bellovin <smb@cs.columbia.edu>
List: netbsd-users
Date: 04/22/2007 19:02:19
On Sun, 22 Apr 2007 18:03:50 -0400
Douglas Allan Tutty <dtutty@porchlight.ca> wrote:
> On Mon, Apr 23, 2007 at 03:25:31AM +0800, Joseph A. Dacuma wrote:
> >
> > > I would be interested in reading a technical comparision of
> > > NetBSD and Debian (not a flame fest or a religious debate) to
> > > understand for example, _why_ the rc system is better than
> > > sysVinit (as implemented by debian), _how_ the kernel differs.
> > >
> >
> > IMHO, rc system is simpler than Debian's or most GNU/Linux distros'
> > System V Init. Theres no confusing /etc/init.d and the numerous
> > links to rcN.d with S or K and XXservice for every run level.
>
> What isn't clear is what order things happen in the rc system. For
> example, if I'm (or advising someone on) tracking down a problem
> related to a service in Debian, I can start in single user mode and
> go down the rcS.d links one at a time with the param 'start'.
> Similar if 'something' is doing 'something', I can suggest they go
> through the rc6.d links one at a time until the 'something' stops. I
> wouldn't yet know how to do that with the rc system.
>
rc.d files have REQUIRES and PROVIDE lines; these form a partial
ordering. A command called rcorder turns those into a linear order.
See /etc/rc -- it's invoked by init, and starts everything else.
--Steve Bellovin, http://www.cs.columbia.edu/~smb