Author: Vic Date: To: hampshire Subject: Re: [Hampshire] Laptop Hardrive
> Yes, if data is actually unrecoverable (as happened in my notebook's
> hard disc: 3 bad sectors at the time of replacement, lost a video) the
> drive will kick up a fuss-load of ATA errors, which will be reported all
> over dmesg.
That's for broken sectors, not sector reallocation; if the data is
actually gone from the drive, there's nothing you can do about it.
The purpose of SMART is to notice impending failures before they get to
such a critical level, and move data away from the failing areas into
spare sectors. It's not perfect but, absent any significant external
events (like dropped disks), it's pretty good.
> (If you see any of them, these messages will indicate the
> *logical* block(s) for which the read failed, but I don't know how to
> map this data back to specific file-system entries.)
debugfs will do that, if you can be bothered. I usually rescue everything
to another drive first (failing drives often degrade while you're trying
to fix the machine), then run "rpm -Va" on it. That catches everything
managed by the package manager...
> In the case here
> the drive probably read back the data after writing to check it, found
> the media wanting, wrote it elsewhere, and blacklisted the sectors.
