Subject: Re: weird messages from "dd if=rwd0d"
To: None <>
From: Christoph Badura <>
List: current-users
Date: 05/05/1999 19:49:03 (Manuel Bouyer) writes:

>You have efectively reached the end-of-media, this is why the command was
>aborted (trying to read beyond EOM). The problem is that, unlike in the SCSI
>world, there is no defined error for this situation (there is only a few
>different errors possible in IDE), so the error reproted in this situation
>is vendor dependant.
>The other error I've seen for this is "ID not found", which is quite accurate,
>but is also used for real hard errors.

And the other error I've seen, as I have reported before, is that at least
one disk goes AWOL and the system hangs.

>One possible thing would be to check the transfer against the disklabel
>even for the raw device, but this changes the semantic of the raw device.

That may change the semantics for sd* devices.  But not for raw disks in
general.  There are other disk drivers that check the raw partition against
the disklabel.  In any case, for IDE and ATAPI disk we know *excatly* the
number of blocks on the device and I don't see a reason why we shouldn't
check against them.
Christoph Badura

	Anything that can be done in O(N) can be done in O(N^2).
	-- Ralf Schuettau (after looking at a particular piece of code)