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I need to recover a 3TB USB HD. I started making a copy yesterday by running ddrescue in Terminal entering:

sudo ddrescue -v -f -n /dev/disk3 /Volumes/Seagate/disk_rescue.dmg disk_rescue.log

I've only just learnt how to use ddrescue so I was thrilled that it worked at all. It got to 1071 GB rescued (with no errors so far!) when I realized that a 2TB destination drive is going to fail when it runs out of space - oops.

I interrupted the copy with Ctrl-C and ran out and bought a 4TB hard drive to use as the destination drive instead. 4TB because I read that it needs to be bigger than the input drive to have enough space for the log file.

So my question: can I resume the copy of my failing hard drive on the new 4TB destination drive using the log file? Or do I have to start again from scratch? It's been running for about 16 hours so far, so if I don't have to start again that's a big time saver.

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Yes you can, just copy the image to the destination drive and adjust the output path accordingly.

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Thanks! Once I've copied the image do I just type in the whole command that I typed before but with the adjusted output path? I can't actually see a .log file anywhere so I'm assuming that I don't have to go find it – Sadira Feb 20 '13 at 1:17
yes, that should work assuming you run the terminal in the same "working directory" as you had it before (i.e. you didn't/don't change directories after you launch(ed) the terminal) – nc4pk Feb 20 '13 at 2:40

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