disk partitioning

[Steve_Kilbane steve@cegelecproj.co.uk]

I've got a disk on a Sun machine with enough space to stick a full plan 9 fs 
on it.
The problem is figuring out the partitioning. Since I can't allocate all of the
disk for Plan 9 (some folks here want to do real work. weird, but there you 
go...),
I need to have the Plan 9 and Sun partition tables in accord. Thankfully,
this isn't the Sun's boot disk. :-)

Problem is, SunOS and Plan 9 have different ideas about the size of the disk. I
presume this is just the operating systems reserving chunks for themselves, and
being "safe" in the case of poor, befuddled users like myself, but it's not
helping right now.

Plan 9 (prep(8)) claims the disk has 4,194,685 sectors, which i take to be
either 4,194,684 or 4,194,686, whatever. SunOS 5.3 claims that there are
4,154,160 accessible sectors out of 5,320,000. So, does anyone have any
suggestions about how I work out how to map one into the other?

A follow-up question about prep - since prep's default table consists of
just plan 9 partitions, i presume it's ok, once prep's generated sdnpartition,
to just edit said file with sam, to insert another partition?

steve