Subject: Re: Installer and root partition roulette
To: None <rnestor@metronet.com>
From: Ken Nakata <kenn@synap.ne.jp>
List: port-mac68k
Date: 07/25/1998 09:22:57
Fri, 24 Jul 1998 16:53:19 -0500, Bob Nestor wrote:
> El JoPe Magnifico <jope@n2h2.com> wrote:
> >Uh... and a no-brainer question: NetBSD uses a ffs file system, right?
> >
> Yes.

If there were a way to distinguish between ext2fs and ffs formats,
could the root device be ext2fs?

> >As soon as the Installer gets the device, it jumps right in and tries to
> >mount everything it can (I assume), and then bombs with a mountfs() error,
> >which half the time hangs my entire system.  In for a penny, in for a
> >pound: Why doesn't the Installer just use the same partition dialogue as
> >Mkfs, seeing as they already use the same device dialogue?
> >
> I believe the Installer uses or tries to use the same lookup scheme as 
> the kernel does. It looks for partition types and validates them looking 
> at the flags.  Since the Kernel does really have a dialogue with the user 
> about selecting partitions for use during boot, making the Installer do 
> this could cause a lot of user problems.  The user might be able to do an 
> Install but not be able to boot up the finished result.

As an alternative, would it make sense if we made Installer and kernel
prefer an AUX Root partition with "NetBSD" in its name over a plain
AUX Root partition?  This "new" root partition will be compatible with
our old kernels (so they'll work as long as there's no Linux partition
on the disk), while "new" kernels and Installer can take advantage of
this change and coexist with Linux.  "New" kernels and Installer will
see the "old" root partition, too, but converting "old" to "new" takes
only changing partition type with Mkfs.

I thought about changing partition type from AUX to "NETBSD" (which is
defined in <machine/disklabel.h> but used nowhere) but it'd have
larger impacts than my suggestion above.

Or maybe we could arrange some kind of agreement with MacLinux people
on partition naming (or type) convention so that both OSes will be
able to distinguish correctly the other's partitions from their own.

Ken