Re: wedges and gpt.

[Herb Peyerl <hpeyerl%beer.org@localhost>]

On Oct 7, 2009, at 6:46 AM, Joerg Sonnenberger wrote:
> > sysinst support is not that helpful as long as the boot support is  
> > not
> > present. Which will hopefully hit the tree very soon now.

What would be nice is having 'gpt' and 'dkctl' in the sysinst root to  
eliminate this step:

cd /dev && sh MAKEDEV drvctl dk7
mount_mfs -s512m swap /mnt
mount -r -t cd9660 /dev/cd0a /mnt2
cd /mnt && tar xzpf /mnt2/amd64/binary/sets/base.tgz
cd /dev ; tar cf - . | (cd /mnt/dev ; tar xvpf - )
chroot /mnt

...but that's off-topic for tech-kern...

> > (1) the 'gpt' command tells you what to type to dynamically create a
> > wedge but the command it spews is not syntactically correct.
>
> The preferable fix would be to trigger a reenumeration by the kernel,
> but that doesn't exist yet.

yup. That'd be cool.  It would have removed some confusion for sure.

> > (3) Do we really need a GPT partition table, then wedges, then an
> > MBR partition table, and then subsequently a BSD disk label?  This
> > onion has a lot of layers.
>
> The idea is that you have only the GPT table. The wedges are just the
> representation of the inidividual entries. There is no need for a disk
> label.

I couldn't newfs anything until I edited the BSD disk label; though  
that could have been a result of confusion on my part...

> > (4) Even once I did get it all working properly, gpt still reports
> > "gpt: rwd0d: Suspicious MBR at Sector 0" and I never did figure out
> > how to make that go away while leaving a functional system.
>
> Are you using bootcamp? IIRC that is doing some strange things.

nope.  I used bootcamp the first time and it screwed things up.  The  
second time I used Apple's "Disk Utility" to shrink my OSX partition  
and then 'gpt' to create the subsequent partitions but that also  
didn't seem to work... On the third attempt, I used "Disk Utility" to  
shrink the OSX partition, and create a second but unformatted  
partition which after the NetBSD boot, I 'gpt remove'd and was able to  
create my Root and Swap partitions...

Between each attempt, I reinstalled OSX from scratch using the whole  
disk for OSX in order to get a completely fresh start.

Finally, it would be cool to be able to 'mount' a wedge by name,  
instead of device... I've always hated our dissociation between  
'mount' and dynamic probing of devices... ie: add a scsi device or  
remove a USB device and after a reboot, your fstab is incorrect...  
We're inviting the same issues with dynamically probing of wedges, I  
think...

This would be cool:

bash-4.0# dkctl wd0 listwedges
/dev/rwd0d: 4 wedges:
dk3: NetBSD-swap, 10000000 blocks at 146301455, type: swap
dk2: NetBSD-root, 129183719 blocks at 17117736, type: ffs
dk1: OSX, 16708096 blocks at 409640, type: hfs
dk0: EFI System Partition, 409600 blocks at 40, type: msdos

...and an /etc/fstab that looks like this:

"NetBSD-root" / ffs rw 1 1
"NetBSD-swap" none swap sw 0 0
"OSX" /osx hfs rw 1 0
kernfs /kern kernfs rw
procfs /proc procfs rw

...or:

mount_wedge "OSX" /osx