How to Save a dying Hard Drive – using dd_rescue

How to Save a dying Hard Drive – using dd_rescue.

By McCartney Taylor

Whoops! Your computer has a dying drive?  Time to act now before it gets unrecoverable.  I had a critical computer on the blink and had to find out how to save it. Here’s my know how for someone else to save their ass as well.

  • 1. Make sure the bios can see the drive. Boot into BIOS and do ‘Disc Detection’ or something like it.  If the BIOS can’t see the drive, it’s too late.  Remember what Bevis said to Butthead, “If you ever drop your keys in a river of molten lava– forget it, Man, they’re gone.”
  • 2. Go download Hitachi’s Drive Fitness test CD. (  Burn the image and boot of the CD.  Run the advanced Test. This will confirm the drive is dying.
  • 3. Once the problem is diagnosed, the solution needs 2 things. A) Spare Hard Drive equal or bigger then the dying one. B) A rescue CD like Knoppix.  First, go get your backup Drive and make sure you have the cable to connect it. However – Don’t connect it yet.
  • 4. Download Knoppix ( or System Rescue CD ( .  I’m fond of both, but I like the System Rescue CD when I’ve got a dying drive.  Either one is a live, bootable CD meaning the CD is a self contained OS you boot off of.  So go ahead and boot off of one of them.
  • 5. Once Booted. Go start gparted. Gparted is going to tell you about the partitions on your bad hard drive.  Write down the exact size of the partition you want, and the info of the serial number. You will do this so you can recognize the bad hard drive from the good. Later you will copy the bad the good. Do this wrong and you might screw up and copy the good to the bad!
  • 6. Now that you know the size of the partition of the bad drive you need to plug in the good drive, make a equal sized partition and salvage what you can.
  • So, turn off the machine and plug in the spare drive.  It may connect to the same cable as the bad drive, or the CD, or you may just snap on its own cable and connect it to a spare IDE, SCSI or SATA jack (whichever kind of drive it is).  Take care to set the drive to the right setting. Like CD/ Slave or Master, opposite of what the other device on the cable is. So if the CD is SLAVE, spare drive should be MASTER.  If the drive is stand alone, it doesn’t matter.
  • 7. Reboot to your KNoppix or SRCD. Start Gparted, it will analyze all drives in the computer and tell you the partition including the new one. Delete all partitions off of the NEW drive if there are any. Create on the NEW drive an exact copy of the partition of the old one. Write down the name of the OLD bad partition and the NEW good partition. It might be hda1 (bad) and hda2 (good)
  • 8. Now open a terminal, it looks like the command prompt of windows.  Type in dd_rescue /dev/hda1 /dev/hda2 which means rescue copy BAD partition to GOOD partition. Screw up the order and you copy nothing from the GOOD drive and WIPE OUT the BAD drive salvaging nothing.  It is easy to think of this with an arrow dd_rescue A –>  B with the destination drive  always on the right.
  • 9. This copy process will copy each sector and when it gets to bad sectors it will try and try to salvage any data reading front to back till it can’t then back to front. This entire copy process may take hours and even up to a day for a large drive with thousands of bad sectors. This is a good thing. It is a devoted employee working into the night for you.
  • 10. When dd_rescue is done, you will have a good disk with most of your data on it.
  • 11. Unplug the bad disk and reboot. It may or may not be bootable depending on how badly damaged the bad disk was. If the good disk is not bootable, you can now plug the good disk into a working computer and remove the valuable data you needed. Or you can restore your version of Windows back on it. (Or Linux)

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