How do hard drives handle bad blocks nowadays?

[Tom Metro]

MBR wrote:
> In particular I recently cloned a laptop drive (IDE) to a 
> new drive.  When I did so, I encountered 2 bad blocks on the new drive.  

What did you use to perform the clone and how were the bad blocks reported?


> After doing some web searches and a bit of reading on this, I get the 
> impression that nowadays all modern drives...handle this behind the scenes.

Correct.


> If that's true, then presumably the only time I should ever see a
> disk report a bad block is when there are no more spare blocks left.
> Am I right about that?

That's my understanding.


> If so, then the fact that I encountered write errors on two blocks on 
> the drive suggests that the brand new drive was in pretty bad shape to 
> begin with.

Unless the error was actually a read error during a verification step.
It is possible to still encounter unrecoverable read errors. Bad blocks
are only remapped on a write operation.


> Is there some tool that will allow me to examine the disk's bad block list?

The specific location of the bad blocks may be something that only a
drive manufacturer's proprietary tools can extract.


> Also, should I use 'dd' to test all blocks before I put a drive into 
> service, or is there a better tool out there?

See the "hard drive burn-in" thread:
http://thread.gmane.org/gmane.org.user-groups.linux.boston.discuss/30555/focus=30559

(BTW, we now have list archives at Gmane:
http://dir.gmane.org/gmane.org.user-groups.linux.boston.discuss
(thanks JABR) which work a bit better than Nabble, which has gone down
hill in recent years.)

 -Tom

-- 
Tom Metro
Venture Logic, Newton, MA, USA
"Enterprise solutions through open source."
Professional Profile: http://tmetro.venturelogic.com/