Hello,

> 1.  Is it really necessary to have installation *floppies* available?
No. Just something to boot NetBSD from.

> I installed my 1.6.2 systems from CD-ROM ISO images, and actually
> don't even have a floppy drive (or the scope to fit one) to one
> machine.   Can I assume that if I can boot from CD-ROM I can also
> upgrade that way?
Yes. I usually upgrade by hand ( read: make a new kernel, replace userland... ) so in theory you can upgrade without any bootable medium besides your harddisk. But of course it's safer to use a CD.

> 2.  Just how much of 2.0 do I have to get installed to have a working
> system?
In a fresh install all you need is a kernel, base.tgz and etc.tgz. Don't forget the MAKEDEV all ritual. This won't have a compiler, X11 and so on but it will be a usable system.

>  Leaving aside anything that involves compilation, can I
> assume backward compatibility for vi, groff, X and so forth (yes, I'm
> an ageing Unix hacker), or should I really be seeing this as a fresh
> installation necessarily?
If you don't delete all the old libs and use a kernel with the right backwards compatibility options (GENERIC usually has them all) things should just continue working. groff, vi and X will be replaced anyway since they're part of the base system.

> It's just that I have work to do as well,
> and ideally I don't want surprises.   Without experience of
> undertaking previous upgrades, I'm wondering if I'm going to find I
> have to reconfigure numerous things I rely on (sendmail, named,
> NFS...)
Usually not. it you replace the etc stuff make sure you take the files you changed out of the way ( ideally that's only rc.conf, hosts, passwd and the like ) so you can put them backwards.

> 4.  Is 2.0 going to want to alter the overall layout of my disk 
Not unless you tell it to :)

> (and BTW why does it say 16 partitions? I've always wondered...)
Because some other ports only (used to) support 8 partitions.

have fun
Michael