"One or more disks are failing" ?

[Bruno Wolff III]

On Sat, Jul 04, 2009 at 13:38:12 +0200,
  Michael Schwendt <mschwendt at gmail.com> wrote:
> 
> In other words, you're playing Russian roulette as you cannot know
> how long the drive will continue to run even with a growing number of
> reallocated sectors. If you decide to keep this drive running, watch
> above value carefully, but even if it doesn't increase quickly, there
> may be sudden death of this drive.

But there can be sudden death without any warning with a chance of the
same order of magnitude. Sure if you have lots of money relative to the
value of the data it's a good idea to change the drive. For hobbiests
it may make more sense to squeeze some more life out of the drive.

> > > 197 Current_Pending_Sector  0x0012   100   100   000    Old_age   Always
> > >       -       2
> 
> This is worse than above. It ought to be zero. The internal hard-disk
> controller has not reallocated these two sectors yet.

Drives typcially won't reallocate bad sectors if they can't get a good read
or the operation is a write. This is to give you a chance to recover the data
if you want to try. And if you want to spend some effort, you can figure out
what files, if any, were using these blocks.