[YLUG] Data recovery End of the story ?

[Patrick Dupre]

Hi Roger,

What can I tell you ?
Do you want to test the drive ????


> On Tue, Jul 28, 2009 at 03:22:42PM +0100, Patrick Dupre wrote:
>> On Tue, 28 Jul 2009, Roger Leigh wrote:
>>
>>> On Tue, Jul 28, 2009 at 12:20:23PM +0100, Patrick Dupre wrote:
>>>
>>>> 1) dd if=/dev/sdx of=/dev/sdy   did not work (incomplet data copy)
>>>
>>> Was this because the destination was too small, or an error
>>> prevented a full copy?
>> No, sdx was 80Go, sdy was 160 !B
>>>
>>>> 2) I was rescued by ddrescue /dev/sdb11 /dev/sdcx
>>>
>>> If dd failed while ddrescue worked, this implies that disk errors
>>> caused the copy to abort.  ddrescue continues on error so that
>>> it copies every /readable/ block, but if particular blocks are bad
>>> they won't get copied.  The implication of this is that your disk
>>> isn't just corrupted, it's broken and needs replacing.
>>
>> I do not think so, the partition table was just a bit messy.
>> and the recover was perfect after a fsck -y
>> the partition was in lost+found dir with a # number.
>> The rest seems perfectly OK.
>
> dd copies raw blocks from your disk.  Whether the partition table was
> messy or not is most likely irrelevant.  The only circumstance where
> it could fail is if the partition extends over the upper size limit
> of the disc (in which case you'll still have as full a backup as is
> practical).  If this was not the case, then your disc is not well;
> fsck might not have detected silent corruption of your data (as
> opposed to the filesystem metadata).  If anything ended up in
> lost+found, then /something/ was wrong.
>
>
> Regards,
> Roger
>
>

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  Patrick DUPRÉ                      |   |
  Department of Chemistry            |   |    Phone: (44)-(0)-1904-434384
  The University of York             |   |    Fax:   (44)-(0)-1904-432516
  Heslington                         |   |
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