Subject: Re: newfs trashes MBR/disklabel?
To: David Laight <>
From: Dieter <>
List: port-amd64
Date: 08/28/2005 08:55:37
> > This is my first system that uses a "MBR" type partition table
> > plus BSD disklabel rather than just a BSD disklabel.  Most likely
> > I have made some MBR newbie error.

> >     Start sec   End sec  Size sec FS type    Newfs Mount Mount point
> >     --------- --------- --------- ---------- ----- ----- -----------
> >  a:        63    204862    204800 FFSv1            Yes   /
> You will wish you made root bigger than that at some point....

Is AMD64 that bloated?  I have a 50 MB root on my Alpha and
other than limiting how many experimental kernels I can have
sitting around in root it hasn't been a problem.  I figured
100 MB should be plenty roomy.

For me, /usr is the partition that runs out of space when installing
all those bloated packages.

> If you intended this to be a partition for the kernel, this isn't
> necessary - the netbsd mbr bootselect code can boot directly from
> one of the extended partitions.

Long term plan is to try and run Xen (I think AMD64 support is supposed
to come out soon), since I need device drivers from FreeBSD and Linux.
So I get to figure out how to run grub, even though several NetBSD'ers
really hate it.  (recent thread in port-xen) Three OSes and some chroot
prisons mean I need a metric boatload of partitions.  Yesterday's attempt
didn't even include partitions for FreeBSD, and I haven't looked into
whether Xen needs any partitions for itself or not.

> I suspect you failed to realise that each 'extended partition' is layed
> out a little like an entire disk.  So there is a gap (usually one track,
> 63 sectors) between the start of the extended partition itself, and where
> the data partition it contains starts.

Ah ha!  I figured that newfs must have overwritten something, but it wasn't
obvious what, since I had left sectors 0-62 for MBR.  Thank you.

Anyway, last night I simplified things, no extended partitions, and
managed to get 2.0.2 installed well enough that it can boot from SATA
and seems happy.  

One more partition question.  Why does port-amd64 need to waste a partition
for "netbsd" (partition c)?  Port-alpha only wastes one partition (for "whole
disk", partition c on Alpha, partition d on amd64) so it would appear that
NetBSD doesn't need it for anything.  Would anything bad happen if I used
partition c for a filesystem?