Re: Transparent compression in the FS

[Jeff Garzik]

Chris Meadors wrote:
> On Thu, 2003-10-16 at 17:02, Jeff Garzik wrote:
>
>
> > I'm curious if anyone has done any work on using multiple different 
> > checksums?  For example, the cost of checksumming a single block with 
> > multiple algorithms (sha1+md5+crc32 for a crazy example), and storing 
> > each checksum (instead of just one sha1 sum), may be faster than reading 
> > the block off of disk to compare it with the incoming block.  OTOH, 
> > there is still a mathematical possibility (however-more-remote) of a 
> > collission...
>
>
> I don't think multiple hashes will gain any more uniqueness over just a
> larger hash value. 

I disagree...

 But as long as the hash is smaller than the block
> being hashed there is the possibility of two dissimilar blocks producing
> the same hash.

Agreed.

	Jeff



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