Re: Help with CHS / geometry

[Martin Husemann <martin%duskware.de@localhost>]

On Sun, Feb 12, 2023 at 01:40:13AM -0500, vom513 wrote:
> sd0: 8715 MB, 8387 cyl, 10 head, 212 sec, 512 bytes/sect x 17850000 sectors

212 sectors x 10 heads give 2120 sectors per cylinder.
2120 x 8387 cylinders gives 17780440 sectors total.

But the drive has 17850000 sectors, as it does not really have that geometry
physically (and nothing cares much about that fact).

The last 17850000 - 17780440 = 69560 sectors will not be accessible with
this "virtual" geometry and a sun label. The kernel will print a note
about this on boot, but this is fine (and it happens for a lot of
"real" drives).

If you just use 17780440 for your image, the kernel output will change to:

sd0: 8715 MB, 8387 cyl, 10 head, 212 sec, 512 bytes/sect x 17780440 sectors

Martin