On Fri Sep 18, 2009 at 12:57:23PM +0300, Majed B. wrote:

Thank you for the insight, Robin.

I already have used dd_rescue to find which sectors are bad, so I
guess I could either wait for Matthias to finish his modifications to
mdadm, or I can reconstruct the bad sectors manually (read same sector
from other disks, xor all, write to damaged disk's clone).

This won't work if your array is degraded though - you don't have enough
data to do the reconstruction (unless you have two failed drives you can
partially read?).

Weird thing though, is that when I re-read some of the bad sectors, I
didn't get I/O errors ... it's confusing!

Odd.  I'd recommend using ddrescue rather than dd_rescue - it's faster
and handles retries of bad sectors better.

Also, I'd rather avoid a fsck when I have bad sectors to not lose
files. I'll run fsck once I've fixed the bad sectors and resynced the
array.

True - a fsck should only be done once the data's in the best possible
state,

Cheers,
    Robin
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