Subject: Re: /etc/inittab (was: /etc/default)
To: None <>
From: Steven Plite <>
List: current-users
Date: 07/27/1995 16:26:29
> so sayeth (Greg A. Woods):
>> More like "from two to a few".  If we want(?) to generalize BSD run levels,
>> why not allow for an arbitrary number?  I can see it now:
> I'll see your ounce of sarcasm and raise you a pound of flexibility.  ;-)

Did I only use an ounce?  My sarcasm sprayer must be clogged. ;)

Seriously, I don't understand why SVR[34] only leaves you one level (#4) to
play with.  If you're adding complexity, at least make it *useful* complexity.
(Granted, you could redefine some of the "standard" run levels, but that's
asking for trouble.)

> The original 8 states by AT&T seem like enough, but why *not* go to
> something like 256?  Who knows what useful possibilities might arise?
> Remember when 16-bit words were enough? ;-)

Exactly.  Of course, more than ten run levels would break the SVR[34]
inittab syntax, but who cares?

>> Why not put all the system-defined levels at the beginning [0-x], and allow
>> [x+1-n] to be user defined?
> If it's a totally generic tool, how (or why) do you specify the difference?

By "system-defined" I mean, "as a shipped default".  You'll probably want your
OS to ship with run levels for reboot, and single/multi user at a minimum.

But you're right; that shouldn't mean you can't change level 0 from "reboot" to "run Doom".

> BTW, the only reasonable argument I've heard against the idea of run
> levels (i.e. making init a full multi-state machine, rather than a
> two-state one) is that the *potential* for obscure complexity in such a
> critical part of the system is too much to risk....  My only answer to

I think the kernel holds the record for Obscure Complexity in a Critical Part
of the System.  ;)  (ducks to avoid the barrage of MS-DOS 2.1 manuals)

> that is that I've always felt highly restricted by the old style init,
> esp. when I needed to do important things at critical times in the
> systems life -- SysV init feels like a breath of fresh air in a big open
> meadow!

Hmmm... I picture SysV init as a breath of fresh air in a big open meadow
with my leg caught in a bear trap.  (sorry, couldn't resist)

I think the generalization from a two-level to a multi-level init would be a
Good Thing.  But I don't consider SysV's init a Good Thing.  What
implementation would I suggest?  Well, there's always MS-DOS 6.x's CONFIG.SYS

I'll shut up now.
Steven Plite  <>       Open Systems Eng. & Support, Weyerhaeuser
    "This is the roller coaster of endless and violent vomit."	-- Jason Fox