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