do I have to worry about these disk errors?

[Bruno Wolff III]

On Sun, Jun 07, 2009 at 18:04:04 +0300,
  Jussi Lehtola <jussilehtola at fedoraproject.org> wrote:
> On Sun, 2009-06-07 at 09:31 -0500, Mike Chambers wrote:
> > On Sun, 2009-06-07 at 16:41 +0300, Jussi Lehtola wrote:
> > 
> > > You can verify the diagnosis with
> > > 
> > > # smartctl -A /dev/sda
> > > 
> > > If you have a nonzero number in one or more of the following fields
> > >   Reallocated_Sector_Ct
> > >   Current_Pending_Sector
> > >   Offline_Uncorrectable
> > > then your hard drive is failing. Especially if you have something in  
> > > the latter two you should panic.

The latter two aren't much different than the first. Drives don't reallocate
sectors until you write over them, to give you a chance to try rereading
them in the hope you'll eventually get a good read.

And unless the counts are high or growing regularly you don't need to panic.
While there is a correlation between bad sectors and drive failure, it isn't
as high as you might think.

If the data is valuable and money isn't a big concern, sure replace the drive
promptly. If you're on a tight budget and you have a way to easily recover
if the drive fails suddenly, then you might play russian roulette. Drives
with a couple of bad sectors can run years before failing.