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Recover Data from a Damaged hard disk using dd_rhelp

Posted by Admin on December 19th, 2006

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dd_rhelp is a bash script that handles a very usefull program written in C which is called dd_rescue, it roughly act as the dd linux command with the caracteristic to NOT stop when it falls on read/write errors.

This makes dd_rescue the best tool for recovering hard drive having bad sectors.In short, it’ll use dd_rescue on your entire disc, but will try to gather the maximum valid data before trying for ages on badsectors. So if you leave dd_rhelp work for infinite time, it’ll have the same effect as a simple dd_rescue. But because you might not have this infinite time , dd_rhelp will jump over bad sectors and rescue valid data. In the long run, it’ll parse all your device with dd_rescue.

You can Ctrl-C it whenever you want, and rerun-it at will, it’ll resume it’s job as it depends on the log files dd_rescue creates.In addition, progress will be shown in a ASCII picture of your device beeing rescued.

Why use dd_rhelp and not dd_rescue ?

dd_rhelp uses dd_rescue to compute a recovery path through the device that will focus on valid data recovering. This recovery path will go through all the device, exactly as dd_rescue could do it on its own without any path. This means that dd_rhelp will save you time ONLY IF YOU INTEND TO CANCEL ITS JOB BEFORE THE END of a full recovery.

Because a considerable amount of time is taken to try to rescue badsectors. This amount of time can be mesured in days,
month, years, depending on your device capacity and its defectiveness. You might not want to spend this time knowing that 99 percent of this time will be taken to look at badsector and won’t lead to any more data recovering.

dd_rhelp shifts this useless waiting time to the end. Using dd_rescue strait throughout your device make your waiting time dependent on the badsector distribution.

Install dd_rhelp

First you need to download latest version from here

Preparing your system

#apt-get install make gcc g++ ddrescue

If you are using ubuntu linux use the following command

sudo apt-get install make gcc g++ ddrescue

Download dd_rhelp using the follwoing command

wget http://www.kalysto.org/pkg/dd_rhelp-0.0.6.tar.gz

Now you have dd_rhelp-0.0.6.tar.gz file

Extract this file using the following command

tar xzvf dd_rhelp-0.0.6.tar.gz

cd dd_rhelp-0.0.6

Run the following commands

# ./configure

# make

# make install

If you are using ubuntu linux use the following command

sudo ./configure

sudo make

sudo make install

This will complete the installation and this will install program under /usr/local/bin/dd_rhelp

dd_rhelp Syntax

dd_rhelp {filename|device} {output-file} [{info}]
or dd_rhelp --help
or dd_rhelp --version

Now we will see how to use ddrescue under damaged disk

If you have a damaged hard disk /dev/sda1 and you have an empty space hard disk /dev/sda2 Now if you want to copy data from /dev/sda1 to /dev/sda2 use the following command

#dd_rhelp /dev/sda1 /dev/sda2/backup.img

If you are using ubuntu linux use the following command

sudo dd_rhelp /dev/sda1 /dev/sda2/backup.img

Output looks like below

/usr/bin/tail: Warning: “+number” syntax is deprecated, please use “-n +number”
=== launched via ‘dd_rhelp’ at 0k, 0 >>> ===
dd_rescue: (info): ipos: 104384.0k, opos: 104384.0k, xferd: 104384.0k
errs: 0, errxfer: 0.0k, succxfer: 104384.0k
+curr.rate: 10178kB/s, avg.rate: 8532kB/s, avg.load: 31.3%
dd_rescue: (info): /dev/sda2 (104391.0k): EOF
Summary for /dev/sda2 -> backup.img:
dd_rescue: (info): ipos: 104391.0k, opos: 104391.0k, xferd: 104391.0k
errs: 0, errxfer: 0.0k, succxfer: 104391.0k
+curr.rate: 355kB/s, avg.rate: 8519kB/s, avg.load: 31.3%
/usr/bin/tail: Warning: “+number” syntax is deprecated, please use “-n +number”

This copies an image of /dev/sda1 to sda2

Now you need to check the backup image consistency this will check for is there any problems with this image.

#fsck -y /dev/sda2/backup.img

If you are using ubuntu linux use the following command

sudo fsck -y /dev/sda2/backup.img

After finishing this checking you need to mount your disk image in to your other hard disk

#mount /dev/sda2/backup.img /mnt/recoverydata

If you are using ubuntu linux use the following command

sudo mount /dev/sda2/backup.img /mnt/recoverydata

This will mount all the data from the backup.img under /mnt/recoverydata now you can try to access the data it should
work without any problem.

Restore image

If you want to restore this image use the following command

#dd_rhelp /dev/sda2/backup.img /dev/sda1

If you are using ubuntu linux use the following command

sudo dd_rhelp /dev/sda2/backup.img /dev/sda1

Copy Disk Image to remote machine using SSH

If you want to copy your disk image to remote machine over ssh you need to use the following command

#dd_rhelp /dev/sda1 – | ssh username@machineip ‘cat /datarecovery/backup.img’

If you are using ubuntu linux use the following command

sudo dd_rhelp /dev/sda1 – | ssh username@machineip ‘cat /datarecovery/backup.img’

This will be prompetd for password of the username you have menctioned in the above command after entering the password

dd_rhelp strats copying obviously it will take some time to copy over the network.

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8 Responses to “Recover Data from a Damaged hard disk using dd_rhelp”

  1. Cal Janus Says:

    Installed and used this script. It was amazing! You saved my boss, and of course me, a lot of stress Thanks for posting this!

    Although I should add that I also tried to use this on a physically damaged drive, and it naturally couldn’t do anything. I had to contact a few hard drive repair companies, and finally got in touch with one that worked well. Everyone was trying like mad to have me ship my drive without a quote! It was like a feeding frenzy! Fortunately I came across a company called Hard Drive . Good site, and the guy in charge really knew his stuff.

    I just thought I should mention this, because although dd_rhelp is really good, in cases of physically damaged hard drives, it won’t help much.

    Cal Janus
    Tech Wizards LLC

  2. Limbers Says:

    Looks very good: however, can somebody point me in the right direction on the makefile? My (ubuntu) command is sudo make install and I’m having trouble:

    robert@Humphrey:~/dd_rhelp-0.0.6$ sudo make install
    make[1]: Entering directory `/home/robert/dd_rhelp-0.0.6′
    test -z “/usr/local/bin” || mkdir -p — . “/usr/local/bin”
    /usr/bin/install -c ‘dd_rhelp’ ‘/usr/local/bin/dd_rhelp’
    make[1]: Nothing to be done for `install-data-am’.
    make[1]: Leaving directory `/home/robert/dd_rhelp-0.0.6′

    Funny! So I looked at the makefile and sure enough, install-data-am is an empty reference. How did you guys get past this??

    Thanks
    Limbers

  3. Kieran Says:

    Hi i keep getting the error message
    Warning: “+number” syntax is deprecated, please use “-n +number”
    and the output file is only 11.9mb big, when it’s copying from a 160gb drive!

    I’m trying to copy from the hard drive dev/hdb (160gb ntfs) to media/Elements (500gb vfat external usb). I heard that vfat format could cause this to happen, any ideas how to get around it?

    Cheers,

    Kieran

  4. VovkaS Says:

    sudo dd_rhelp /dev/sda1 – | ssh username@machineip ‘cat /datarecovery/backup.img’

    sudo dd_rhelp /dev/sda1 – | ssh username@machineip cat > “/datarecovery/backup.img”

  5. joe b Says:

    my hard drive fell off my bed and when i connect it i hear this whirling or grinding noise on and off…..my mate says it will be the read/write heads is there anyway of retrieving the files as it no longer registers with my computer:( please help

  6. Dave Says:

    I have a damaged Internal HDD (Maxtor SATA 500GB) When I check in vista I see Device I/O Error and it shows there is 0MB data stoted on it, and also I cannot see the partions I created before.
    SO Can I use this way to back data?

  7. Rick Says:

    Joe, Dave

    Go to my harddrive died dot com putting all this together of course. Watch the videos, Scott Moulton is leading the industry in hardware data recovery. He explains how to do most data recoveries for under a 100$. I have personally followed his explanations and did platter swap, head swaps, pcb board swaps. In your case your plobably going to need to do a head swap. What ever you do don’t turn that HD on again, everytime you turn it on it is scratching more of your platters.

  8. san Says:

    i got a maxtor 80GB hard disk as my secondary data storage.its worked properly past 4 years. but now its not detected by computer.can any one say me how can i recover all data without any lost.please its urgent

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