Fixing a crashed disk

[Robert Nichols]

On 10/26/2012 06:29 PM, Steven Stern wrote:
> I quite stupidly unplugged my computer today when my foot got tangled in
> the power strip.  On reboot, I was notified
>
> Device: /dev/sda [SAT], 8 Offline uncorrectable sectors
>
> Smartctl tells me the problem is at LBA 2014551336 (this is a 2TB disk).
>
>
> Following the info here
>
> http://kaivanov.blogspot.com/2010/09/fixing-disk-problems-under-linux-with.html
>
> I'm not able to determine what file might be sitting on this block.
>
> tune2fs -l /dev/sda5 |grep Block
> Block count:              472552448
> Block size:               4096
> Blocks per group:         32768
> [root at sds-desk-2 ~]# debugfs
> debugfs 1.42.3 (14-May-2012)
> debugfs:  open /dev/sda5
> debugfs:  icheck 235992741
> Block   Inode number
> 235992741       8
> debugfs:  ncheck 8
> Inode   Pathname
>
> This suggests that the problem is not in a currently extant file.
>
> I'm now trying the suggestion of writing from /dev/zero to a file in
> /home while in single users mode.  Given that I have 1.5TB to fill,
> this could take a while.
>
> Here's the question:  If I just reformat and restore /home from a
> recent backup, will the disk automatically deal with the sectors
> pending reallocation?

The pending sectors will be reallocated only when they are written to.  Unless
invoked with the very slow "-cc" option, mke{2,3,4}fs will write only to the
metadata areas, and restoring /home will of course not write to any remaining
free space.

-- 
Bob Nichols     "NOSPAM" is really part of my email address.
                 Do NOT delete it.