[509] in linux-scsi channel archive
Re: Buslogic BT946C/Seagate 15150N geometry troubles
daemon@ATHENA.MIT.EDU (Kevin McCormick)
Tue Aug 15 10:04:51 1995
Date: Tue, 15 Aug 1995 03:13:31 -0400
From: Kevin McCormick <fbyte@sub-zero.mit.edu>
Reply-To: Kevin McCormick <fbyte@sub-zero.mit.edu>
To: jered@vorlon.mit.edu
cc: linux-scsi@vger.rutgers.edu
In-Reply-To: <199508150053.UAA13039@vorlon.mit.edu>
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.
This is the technique I've used on both my SyQuest 44MB removable and my
650MB Ricoh magneto-optical drive, and it has worked flawlessly.
(btw, note that the h/c/s numbers won't be preserved by fdisk, so if you plan
on partitioning again in the future, you really should write down what
you used for h/c/s so you don't have to play around to find a good
combination again.)
-------------------------------------------------------------------------------
Kevin "Frostbyte" McCormick kmccorm@mit.edu - root@sub-zero.mit.edu
Mass. Inst. of Technology You should be running Linux!
Q: How many Microsoft engineers does it take to screw in a light bulb?
A: None. They just define darkness as an industry standard.
