[Tfug] Drive recovery

[Bowie J. Poag]

dd is completely unaware of what a sector is -- It's completely agnostic 
when it comes to input. The idea is, recover what can be 
recovered--there's no point in obsessing over  the unreadable. Since 
we're telling it to read off a block device, it becomes the 
responsibility of whatever storage driver is handling the requests to 
satisfy dd. All dd wants is "next, until there is no more "next" to 
read. The resulting iso image might be sane enough to repair and then 
have its contents dumped into a new filesystem.


Bexley Hall wrote:
> --- On Wed, 6/3/09, Bowie J. Poag <bpoag at comcast.net> wrote:
>
>   
>> Image the drive using dd.. Then run fsck or whatever tool
>>     
>
> Won't dd(1) complain when the sector(s) in question return
> read errors?  (I'd have to check the sources to see for sure)
>
>   
>> you choose 
>> against the resulting image. Get a new drive and repopulate
>> it with cp -vR.
>>
>> dd if=/dev/whatever of=/mnt/bar bs=1048576
>>
>> (..run whatever tools you want..)
>>
>> mount -o loop /dev/whatever /mnt/bar
>>
>> cp -vR /mnt/bar/* /mnt/newdrive
>>
>>
>> John Gruenenfelder wrote:
>>     
>>> I've recently had a drive at work begin the throes of
>>>       
>> death.  While SMART did
>>     
>>> not warn me about any problems beforehand, it did tell
>>>       
>> me later that the drive
>>     
>>> had run out of spare sectors.  Some random sector
>>>       
>> went bad, but the drive no
>>     
>>> longer has any spare sectors left in its pool to remap
>>>       
>> the bad one.
>>     
>>> This means that any attempt to read data from that
>>>       
>> sector results in a low
>>     
>>> level read error from the drive.
>>>       
>
> ....^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>
>
>       
>
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