About USB hard drives and errors

[Paul E Condon <pecondon@mesanetworks.net>]

I want to use the low cost high capacity hard drives that are
for sale in places like Best Buy and Costco. I have put ext3 on
several of them and started experimenting. The results so far
are puzzling. 

I do get errors. So I decided to do scans for bad blocks.  The drives
I'm using are all Western Digital because they have been the lowest
cost at the times I buy at Costco. Also all are 500GB.
 
e2fsck -c <device> is supposed to scan for bad blocks and allocate them
to a special inode so that they cannot be used. It runs for 3 to 4
hours and then says its finished with no indication of how many bad
blocks it found.

dumpe2fs -b <device> is supposed to print the bad blocks that have
been marked on a device. When I run it, it prints nothing. I find it
hard to believe that a 500GB HD contains ZERO bad blocks. Especially
one on which I have witnessed error messages about I/O errors in
writing the journal. I can find no information about what, exactly,
dumpe2fs is supposed to print. The wording seems to be that it prints
the contents of the bad blocks. But in other places it seems that it
prints a list of block numbers, or maybe cylinder/sector/head. Since I
see nothing, I don't have a clue as to what I should see.

Has anyone ever used these programs? Have you ever seen useful output?
What SHOULD they do (with a little more specificity and believability)?

-- 
Paul E Condon           
pecondon@mesanetworks.net