*BSD News Article 6417


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From: bs@Germany.EU.net (Bernard Steiner)
Newsgroups: comp.unix.bsd
Subject: Re: HELP: wiped out my DOS partition
Date: 13 Oct 1992 10:27:50 GMT
Organization: EUnet Backbone, Dortmund, Germany
Lines: 48
Distribution: world
Message-ID: <1be8b6INN9pi@Germany.EU.net>
References: <1992Oct5.150129.27179@unibi.uni-bielefeld.de> <1apomrINNi8c@uwm.edu> <16808@ksr.com>
NNTP-Posting-Host: walhalla.germany.eu.net

In article <16808@ksr.com>, dean@ksr.com (Dean Anderson) writes:
> The PC BSD's should look at the dos partition table and create multiple
> logical disk drives, one for each partition.

I beg to differ.
There is no such thing as a "dos partition table" on either of my drives :)

> This has the following benefits:
> 1. Doesn't change machine independent code.  This makes it easier to
> integrate future changes to BSD code, and contribute changes back to
> Berkeley.

Well, the code you propose *is* sort  of machine-dependent, isn't it ?
I mean, I don't have DOS.

> 2. Makes it possible to mount Dos "drives".  A dos vfs is needed.

I recently re-compiled mtools to read the C: drive on some other machine.
The only thing that you really need is yet another definition (disklabel)
for all your DOS fdisk partitions. On a *HUGE* drive you may run into
problems since the number of partitions on a drive is restricted to
eight (if I recall correctly), and on your primary BSD drive at least (I
imagine) the a,b,c and d partitions are pre-allocated (though only c and d are
magic). This doesn't hold for a secondary drive where you are free to use
a and b as you like.

How about making dos vfs aware of the d "partition" only and telling each dosFS
its offset and length ?

> 3. Makes it possible to ignore that dos exists and use the whole drive
> without a dos partition table.  This is particularly attractive is you
> have a large disk,  because dos will not work happilly with disks of
> greater than 1024 cylinders without a lot of egregious hacking which
> ultimately hurts ufs performance.

Huh ? As I said before, DOS doesn't exist, there's no dos partition table...
But then I don't quite understand what you're getting at here.


Cheers,
	Bernard
-- 
Bernard Steiner, FB Informatik/IRB, Uni Dortmund,    vox +49 231 755 2444
Postfach 500500, D-W-4600 Dortmund 50, Germany       fax +49 231 755 2386
bs@Germany.EU.net          ...!uunet!unido!bs

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