Thursday, July 11, 2019, 5:47:36 AM, you wrote: > On 11/07/2019 01.43, Andrey Zhunev wrote: >> >> Ok, the ddrescue finished copying whatever it was able to recover. >> There were many unreadable sectors near the end of the drive. >> In total, there were over 170 pending sectors reported by SMART. >> >> I then ran the following commands: >> >> # smartctl -l scterc,900,100 /dev/sda >> # echo 180 > /sys/block/sda/device/timeout >> >> But this didn't help at all. The unreadable sectors still remained >> unreadable. >> >> So I wiped them with hdparm: >> # hdparm --yes-i-know-what-i-am-doing --write-sector <sector_number> /dev/sda > This has always eluded me. How did you know the sector numbers? When you use ddrescue (or any other tool) to try and read the data and there is a read error, an error message is added to your kernel log. You can find the sector number there: Jul 10 11:56:01 mgmt kernel: blk_update_request: I/O error, dev sda, sector 157804112 You can then try to re-read that specific sector with: # hdparm --read-sector 157804112 If that one still gives an error - then you're sure you can wipe it. > At this point, I typically take the brutal approach of overwriting the > entire partition (or disk) with zeroes using dd, which works as a > destructive write test ;-) > Previous to that, I attempt to create an image with ddrescue, of course. >> >> I then re-read all these sectors, and they were all read correctly. >> >> The number of pending sectors reported by SMART dropped down to 7. >> Interestingly, there are still NO reallocated sectors reported. > I suspect that the figure SMART reports only starts to rise after some > unknown amount of sectors have been remapped, so when the numbers > actually appear there, it is serious. Hmmm, this is an interesting thought! Everybody lies... :) --- Best regards, Andrey
