I thought Hamming codes were a little sophisticated -
whereas Raid-5 parity simply does an XOR across
the data blocks to generate the parity block. That
way ANY one block is equivalent to the XOR
across all the other blocks in same stripe, which
is why you can reconstruct any failed block if
you have all but one of the blocks in the stripe.
--
Regards
Jonathan Lewis
http://www.jlcomp.demon.co.uk/faq/ind_faq.html
The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/seminar.html
Optimising Oracle Seminar - schedule updated Sept 19th
"Frank van Bortel" <fvanbortel_at_netscape.net> wrote in message
news:cprmib$q43$1_at_news1.zwoll1.ov.home.nl...
>
> In addition to the redundancy in data, the Hamming codes
> used for parity calculations, can recreate the missing
> parity bit from remaining disks, thus allowing one disk
> to go bad.
> However, 2 bits cannot be recalculated
> (aka when 2 disks go bad: failure).
>
Received on Fri Dec 17 2004 - 01:54:09 CST
