Failing Disk

[Jim Canfield]

George Magklaras wrote:
> Jim, I disagree with you. I would be interested to know how dd would 
> handle read errors on the failing drive. :-) Have you completed many 
> rescue operations with drives whose reliability is questionable 
> without hickups only with dd???
>
> If his failing drive is in a bad state and is likely to give 
> persistent I/O errors, doing a dd the way you describe it in your 
> number list will either abort the read operation or copy things 
> inconsistently. Again I would substitute dd with dd_rescue. If his 
> blocks are OK, dd_rescue will behave exactly as dd. If the blocks on 
> the origin drive are broken, it will persist until it copies as much 
> data as possible.
>
You are right, I mentioned previously he may have problems if the drive 
was actually failing,  dd_rescue never even came to mind.  Thanks for 
pointing it out.

-Jim
>>
>>  
>>    Mark,
>>
>>    Did I give bad advice?  I have used dd quite a bit and never had any
>>    problems.  Granted I am always copying to identical drives.  Now 
>> that I
>>    think about it, it would be important to have identical disk geomerty
>>    (cylinders, heads, sectors).  Sorry Troy, guess I'm exposing my 
>> ignorance.
>>    :)
>>
>>    -Jim
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