Subject: Re: MTD devices in NetBSD
To: Terry Moore <>
From: Charles M. Hannum <mycroft@MIT.EDU>
List: tech-kern
Date: 03/23/2006 16:59:15
On Thu, Mar 23, 2006 at 03:49:36PM -0500, Terry Moore wrote:
> Yes, but because of lack of rotational latency sometimes people do
> things substantially differently.  Also, non-local error properties
> of NAND flash change things.  Erase blocks in NAND are some multiple
> of sectors.  Writing a sector in an erase block can cause other
> sectors in the erase block (that you've already written and verified)
> to grow errors.  As far as I know, the error properties of CD-RWs and
> DVDs are not as bad as this.

Actually, they are.  Sectors are interleaved pretty aggressively to
disperse multi-bit errors from scratches, so writing one sector can in
fact damage other sectors -- possibly worse than in NAND flash.