Re: [gentoo-user] disk error, where?

[Volker Armin Hemmann]

On Monday 17 January 2011 21:46:39 Stefan G. Weichinger wrote:
> Am 2011-01-17 21:13, schrieb Alex Schuster:
> > Uh-oh. I suggest emerging badblocks, and then do a 'badblocks /dev/sdb'
> > to see which and how many blocks are defective. You can also replace
> > sdb by sdb6 or whatever partition you are specifically interested in.
> > You also might want to use the -n option (non-destructive write mode),
> > but only on partitions that are not mounted / used.
> >
> > smartmontools also offer some diagnostic features. Including a full
> > surface check, but it stops at the first error. At least you know then
> > until which sectory the drivs is still okay:
> > smartctl -tlong /dev/sdb
> > wait...
> > smartctl -l selftest /dev/sda
> >
> > smartctl -a /dev/sdb also shows lots of info, including the number of
> > bad
> > and reallocated sectors.
> >
> > If cou can, make a copy of the partiton(s) drive with ddrescue (or dd-
> > rescue, don't know which one is better, but both are more tolerable to
> > errors than dd is).
> >
> > I had drives with single errors that seems to work fine for years after
> > this, but I do nto put important data on them. And it is also possible
> > that you had a head crash and more and more sectors become defective.
> > So do the backup fast, or do not use the drive until you do. Good luck!
>
> Thanks, Alex ... I will use badblocks and smartctl in more detail after
> having the data off the drive (as mentioned in my reply to Mark's
> posting right now).

if the disk has spare sectors, it will map out the sector the next time there 
is a write to it. So.. no need to offline it.