Subject: Re: A new partition handling scheme: wedges
To: Greg Hudson <ghudson@MIT.EDU>
From: Manuel Bouyer <>
List: tech-kern
Date: 01/26/1998 19:24:55
On Jan 26, Greg Hudson wrote
> I want to second this.  I deal with supporting NetBSD at MIT
> (NetBSD-Athena, really, but that's not relevant here), and while the
> people here are relatively bright and can understand disklabels
> without too much trouble, they generally find it incredibly Byzantine.
> Why do they have to edit the disklabel and plug in sector offsets and
> lengths to access their DOS partitions?
> It doesn't help that the disklabel program is so querulous about
> labelling a disk for the first time ("disklabel -e" should probably
> work, but doesn't) or that NetBSD doesn't currently understand
> extended partitions.  But even if you fixed those problems, having to
> reconcile the NetBSD disklabel with the MBR every time you make a
> change to the latter is poor.

You could very well have wedgeconfig read NetBSD disklabekl, and create the 
needed devices for the partitions here, and then read the other label
present on the disk and create a devices for each partition found.
This way you don't need to enter the other partitions in the NetBSD's
disklabel if you want to use them, but this allow you to use a different
partitioning of the disk for NetBSD if you need.
(here is a case where I want different partitions in a multiboot environement:
it seems that 2.0.x linux kernel can't handle properly swap
partitions > 128Meg, so you have to create 2 partitions in order to have
more than 128Meg of swap. So you would have 2 contigous Linux swap
partition, which you can collapse in one big swap partition in the NetBSD

Manuel Bouyer, LIP6, Universite Paris VI.