Subject: Re: A new partition handling scheme: wedges
To: Charles M. Hannum <>
From: Chris G. Demetriou <>
List: tech-kern
Date: 01/25/1998 21:34:31
> Here I propose a new way of handling partitions in NetBSD.  This
> proposal is aimed at addressing some problems that have not been
> addressed in previous proposals or implementations (including our
> current scheme and `slices').  I call the idea `wedges'.
> [ ... ]


A few thoughts/questions/comments:

(1) what's the 'native' way of storing wedge information, if any?  You
indicated that you'd want wedgeconfig to be able to understand all the
partitioning types we currently support, but you don't provide a
tool/format to store this information.  Some stable, per-disk storage
mechanism is necessary.  That might be 'disklabel,' but that seems
... less than optimal for what you're proposing.

(2) How do you mount root off of an alternate root device, e.g. when
booting with 'askname' or if the kernel doesn't 'understand' the
device you've booted from (e.g. can't get to it, because it's on a
controller for which there is no driver; not as odd as you might
think)?  "Please don't say you have to specify block offsets."
This isn't really a 'legacy' need, so it's not clear to me that the
pseudo-device you suggest would be particularly appropriate.

(3) "When random potential users see this, what other thought are they
going to have than that NetBSD developers engage in random drug
testing?"  Partitions of various flavors have well-known and
well-understood behaviours.  (Even Mac people understand partitions,
though"Slices" are generally understood as well.  When a sysadmin
familiar with another UNIX-ish system (or even many non-UNIX-ish
systems) sees this, why are they going to have any other reaction than
to run so fast to get away that they leave a body-shaped cutout in a
wall?  Whether or not these things can be made (via documentation)
understandable to someone familiar with the concepts of partitions and
"slices," whether or not they provide a few extra features, they are
utterly alien and unlike anything that I, for one, has ever seen
before.  I'm not sure that an administrator would feel comfortable
trying to get this new-fangled wedge stuff to work right, and that
means that NetBSD is harder to use and understand, which means that
other systems -- whether or not they have more nifty features in this
area -- are going to be considered more palatable.

Sure, this might be better in some ways, but it's a hell of a lot
different and that may be a bad thing in and of itself.