Re: Linux Kernel Summit

On Mon, Apr 02, 2001 at 06:24:00AM -0500, Jim Blandy wrote:
> Greg Stein <gstein@lyra.org> writes:
> > * Use some kind of checksum on the wire and in the DB. Given that whatever
>...
> I think someone pointed this out a while back. The skels for
> deltafied storage include checksums. There's no external FS interface
> for retrieving them at the moment, but that's a few minutes' work.

Ah. I see that in "structure". Two points there:

1) the checksum probably ought to go on both clear text and on deltas

2) MD5 is a hash algorithm rather than a checksum
   (although, now that I think of it, is any checksum algorithm anything but
    a hash? mebbe GregH can clarify the hash vs checksum terminology)

We would then want an API to set the checksum, and one to fetch. I'm not
sure that the FS needs to compute or verify the value at any point. The
client will compute it, Apache will verify it, and a (weekly) cron job can
scan the database verifying records against their stated checksums.

Cheers,
-g

-- 
Greg Stein, http://www.lyra.org/