Subject: Re: Of SCSI disks and things amiss
To: der Mouse <mouse@Collatz.McRCIM.McGill.EDU>
From: Eduardo E. Horvath eeh@btr.com <eeh@btr.btr.com>
List: tech-kern
Date: 03/05/1996 15:29:50
On Fri, 1 Mar 1996, der Mouse wrote:

> > If a disk reported the *actual* size, would it not be possible tell
> > which sectors were phsically in the same cylinder?
> 
> No, unfortunately one can't.  There is no way to ask the disk itself,
> and with modern disks the sectors-per-track value varies depending on
> the cylinder number, so you can't work it out from the cylinder number
> without knowing the details of _how_ sec/trk varies with cylno.

That is not entirely correct.  I recall that the SCSI II specification 
provides for a sense page that describes devices that use zone 
recording.  Whether manufacturers correctly report these values is 
another issue entirely.

Eduardo