Subject: Re: DEV_B_SIZE
To: None <email@example.com>
From: Steve Byan <firstname.lastname@example.org>
Date: 01/31/2003 16:06:43
On Friday, January 31, 2003, at 02:55 PM, Jamey Kirby wrote:
> Who will do the translation?
> Will there be a device driver that makes the 4K disk look like a 512
> byte disk?
> If so, the device driver would have to pre-read the 4K,
> modify the 512 byte section and re-write the entire 4K. This would kill
Yes, it would.
> If this will be handled in the drive, the same sort of logic must be
> employed and surly there will be a performance problem; unless the
> will be able to write the 512 bytes without a pre-read.
Yes, there surely would be a performance problem if the I/O has to wait
for a read-modify-write. There may be proprietary techniques for hiding
the cost. The assumption is that this is purely a
backward-compatibility case, and the performance hit would motivate
folks to update their software to recognize the new larger block size.
Steve Byan <email@example.com>
333 South Street
Shrewsbury, MA 01545