Re: Enabling Checksums

On Fri, 2012-11-09 at 20:48 +0100, Markus Wanner wrote:
> Given your description of option 2 I was under the impression that each
> page already has a bit indicating whether or not the page is protected
> by a checksum. Why do you need more bits than that?

The bit indicating that a checksum is present may be lost due to
corruption.

> However, we certainly need to provide the option to go through the
> rewrite for other users, who are well willing to bite that bullet.

That's the use case that I've been focusing on, but perhaps you are
right that it's not the only important one.

> Do you see any real foot-guns or other show-stoppers for permanently
> allowing that in-between-state?

The biggest problem that I see is a few bits indicating the presence of
a checksum may be vulnerable to more kinds of corruption.

Regards,
Jeff Davis