Subject: Re: two disks, two controlers, same bad block
To: Manuel Bouyer <bouyer@antioche.eu.org>
From: Steven M. Bellovin <smb@cs.columbia.edu>
List: tech-kern
Date: 03/27/2006 11:53:25
On Mon, 27 Mar 2006 18:40:34 +0200, Manuel Bouyer
<bouyer@antioche.eu.org> wrote:

> On Mon, Mar 27, 2006 at 09:36:40AM -0500, George Georgalis wrote:
> > >Seagate gets it wrong. 268435455 is 0xfffffff, a valid sector number
> > >for LBA but which is not handled properly by seagate firmwares.
> > >The workaround is to use LBA48 for this sector number.
> > >
> > >The attached patch should catch all seagate drives that needs it; it's in
> > >current but not in 3.0.
> > 
> > humm, this is starting to remind me of a similar issue I came
> > across in Linux. the patch caused the disk bandwidth to drop by
> > about 65%. Is that the case here? I would really prefer to
> > mark that block as in use...
> 
> I don't know as I don't have such drives here to test. But you could test
> by yourself.
> But if using LBA48 cause a 65% performance drop for these drives, they're
> even more buggy than I though :) Note that LBA48 is required for any sector
> above 128G.
> 
The badsect will grab the sector, but is the problem exactly that
sector or all sectors past that point?

		--Steven M. Bellovin, http://www.cs.columbia.edu/~smb