a way to recover the DB of a data/ directory from a corrupted disk?

Hello,
my case is quite difficult, I think, so all the help
you can give me is more than welcome!

The short story: I had two disks, the primary running
the database server (pg 7.1.2), the second having the
daily pg_dump's. The first disk started to have I/O
problems, the sencond disk was erased by mystake by my
server provider (arrrg!). So the only thing that I
have right now is a cp that I did from the data/
directory of the disk # 1, the one that were running
the database server I got I/O problems. During the cp,
I got some problems doing it, saying things like I/O
erros and the like (bad blocks), so probably around
20% or so of the files are corrupted or were not
copiead at all.

My question is, what can I do in such a case? =(
Is there a way to recover as much as possible?, how?

Thanks for all your help!
Rocael.

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