Partining was Re: multiboot OpenBSD

[Woodchuck]

On Fri, 22 Feb 2008, Tony Abernethy wrote:

> # disklabel -E wd0

-E is the "hand holding mode".

To really futz with a disklabel try just editing it with vi
or reading/writing the disklabel to a diskfile or the /etc/disktab.
These are obsolescent -- but not obsolete -- methods.

Look at the -e, -R, -f and some of the other disklabel options.

I don't think OpenBSD 1.0 came with this -E.  I have clear memories
of using vi on disklabels with peecee BSD.  NetBSD (I think) has a
different switch for "hand holding", which seems to reinforce this
memory.

NetBSD (the parent of OpenBSD for those weak in BSD history) also
has a dedicated "d" disklabel partition; it covers only the BSD partition,
I think.  

> At this point, something is surely wrecked, HOWEVER
> I can log in again and disklabel now gives
> 
> 16 partitions:
> #        size   offset    fstype   [fsize bsize   cpg]
>   a:   307377       63    4.2BSD     2048 16384   304   # (Cyl.    0*- 304)
>   b:   716688   307440      swap                        # (Cyl.  305 - 1015)
>   c: 488397168       66    unused        0     0        # (Cyl.    0*-
> 484521*)
>   d:  3072384  1024128    4.2BSD     2048 16384   328   # (Cyl. 1016 - 4063)
>   e:  1024128  4096512    4.2BSD     2048 16384   328   # (Cyl. 4064 - 5079)
>   f: 51200352  5120640    4.2BSD     2048 16384   328   # (Cyl. 5080 -
> 55873)
>   g:  1024128 56320992    4.2BSD     2048 16384   328   # (Cyl. 55874 -
> 56889)
>   h: 431046945 57345120    4.2BSD     2048 16384   328  # (Cyl. 56890 -
> 484515*)
> disklabel: partition c: partition extends past end of unit
> 
> Not foolproof, but more forgiving that I would expect.

A trainwreck waiting to happen, probably at the next reboot.  But
I bet if you put it back it would be rebootable.

The terminology, with the two distinct uses of 'partition',
is a tremendous hurdle to understanding.

A dual boot situation leads to more "interesting" disklabels.

Dave
-- 
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