On Wed, Jul 26, 2000 at 10:38:09PM +0200, Federico Lupi wrote:
> I have added the following disk to a NetBSD machine:
>   IBM  DCAS-32160, SCSI-3
>   Formatted device capacity: 2.16GB
>   Sector size: 512
>   Data heads: 3
>   Disks: 2
> 
> The output from dmesg is:
>   sd0: 2063MB, 8188 cyl, 3 head, 172 sec, 512 bytes/sect x 4226725 sectors
>                                                            ^^^^^^^ 
> 
> but 8188*3*172 is 4225008 and not 4226725.

hehe, real vs fake geometry. For modern disks the number of sector per track
isn't constant (disk speed and density is constant, so something has to
be variable :), so the above math does't work.
Disk still reports C/H/S geometry but they don't exactly match the hardware.

--
Manuel Bouyer <bouyer@antioche.eu.org>
--