[511] in linux-scsi channel archive
Re: Buslogic BT946C/Seagate 15150N geometry troubles
daemon@ATHENA.MIT.EDU (Andrew Walker)
Wed Aug 16 00:35:16 1995
From: andy@keo.kvaerner.no (Andrew Walker)
To: fbyte@sub-zero.mit.edu
Date: Tue, 15 Aug 1995 16:18:28 +0200 (MET DST)
Cc: jered@vorlon.mit.edu, linux-scsi@vger.rutgers.edu
In-Reply-To: <Pine.3.89.9508150326.A16507-0100000@sub-zero.mit.edu> from "Kevin McCormick" at Aug 15, 95 03:13:31 am
Kevin McCormick wrote:
>
> On Mon, 14 Aug 1995 jered@vorlon.mit.edu wrote:
>
> > Has anyone successfully configured the Seagate Barracuda 15150N 4 GB SCSI
> > hard drive with the BusLogic 946C? Under DOS, I can see the whole hard
> > drive with the BTfdisk program, but fdisk for Linux complains that I need
> > to set the number of heads, and I can't get the DOS fdisk to tell me
> > how many heads/cyl/sectors it thinks the drive has. Does anyone have the
> > correct numbers for this drive?
> >
> > --Jered
> > jered@mit.edu
>
> If I recall, you'll have to make up the numbers. Since SCSI does not use
> the dain-bramaged DOS and BIOS head/cylinder/sector scheme, but Linux
> fdisk still expects it, you'll have to make Linux fdisk happy with some
> numbers that closely represent the size of your drive. Using the equation
>
> (heads)*(cylinders)*(sectors)*512 = bytes
>
> ... play around with the heads, cylinders, and sectors numbers (within
> the limits imposed by fdisk) to get a result (the "bytes") thst is just
> slightly less than the actual number of bytes on your drive. The DOS
> program you used (or something similar) should be able to give you the
> exact number. Don't just multiply it out with the manufacturer-provided
> "4294 MB" or whatever; you most definitely do NOT want to tell fdisk that
> you have more space than you really do. Let the *drive* tell you how
> much space it *really* has. Pick the h/c/s numbers, tell them to fdisk
> in the Extra Functionality menu, then partition away to your heart's content.
Please - don't do this. To re-iterate what Leonard Zubkoff already wrote -
Enable the >1GB support on the Buslogic card. Use 1.2.13 or a 1.3.x
kernel to get the corrected support for >1GB mapping on the Buslogic
card. Linux' fdisk will then get a valid set of values from the
Linux kernel, which will agree with btfdisk.
Only follow Kevin McCormick's advice if you really, absolutely, do not *EVER*
want to access this disk from MS-DOG!!!!!!! Even then I wouldn't do it, as
there's no reason not to use the natural Buslogic >1GB mapping.
Hope this helps,
-Andy
P.S. Theoretically you might need to upgrade your Linux fdisk as well - but
I could be talking out of my hat here.
--
Andy Walker Kvaerner Engineering a.s.
Andrew.Walker@keo.kvaerner.no P.O. Box 222, N-1324 Lysaker, Norway
......if the answer isn't violence, neither is it silence......
