Subject: Re: rc.d (some debates never die :-) (Re: NetBSD 1.5 on uVAX
To: Todd Vierling <tv@wasabisystems.com>
From: Chuck McManis <cmcmanis@mcmanis.com>
List: port-vax
Date: 12/27/2000 20:22:09
At 09:04 PM 12/27/00 -0500, Todd Vierling wrote:
>I presume you aren't blaming NetBSD's incarnation here? After all, our rc.d
>is not like the other systems at all: it has been spcifically designed with
>the lessons learned from the previous methods in mind.
I haven't used it enough to decide if it succeeds where the others fail.
However, the entire "rc.d" concept is based on the flawed (IMHO of course)
assumption that a file system based database is ever adequate. Now the RC
system "expressed" as a file system and based on a database? That might
have some possibilities. But the problem that one is trying to solve is the
one alluded to earlier:
"How can I customize the initialization and shutdown phases
of system operation in such a way that all dependencies
are accounted for and attempts to violate assertions of the
modules are disallowed?"
And to solve this problem you need a vocabulary that can express
interdependencies, transient relationships, and rules of invariance. The
file system with its hierarchical names and symbolic links is not
expressive enough to capture these attributes and hence applications to
manipulate the same are overly complex and prone to failure.
That said, I don't like or dislike the current rc.d/ system, I only share
my observations with others that it places an excessive burden on less
powerful compute platforms. Is that burden to much? Certainly that is a
subjective question which can only be answered subjectively. Is that burden
sufficient to prevent adoption of 1.5 on some platforms, the answer is
clearly yes to that question.
--Chuck