How to restore .dd disk image?

Using PhotoRec to recover lost data
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andrewclam
Posts: 3
Joined: 07 Mar 2012, 21:29

How to restore .dd disk image?

#1 Post by andrewclam »

Hello Everyone,

I have a Seagate Barracuda ST3000DM01 3TB hard drive that used to be in an external enclosure (Seagate External Expansion drive 3TB). I had a pretty bad power-outage in my neighborhood when I was recording TV onto my drive prior. My Windows 7 system could no longer open the hard drive and it wants to format it, I suspected bad sector(s) and corrupted partition table may be the cause of it, so here is what I did.

(1)Got myself a 450w battery-backup surge protector

(2)Used TestDisk to find the lost partition, and found it YAY (Using GPT partition table type, an NTFS labled backup drive), deleted the partition table on the drive, replaced with the one found with TestDisk, no luck, Windows 7 still wants to format it.

(3)Tried using PhotoRec to recover the files, but the PhotoRec process will become unresponsive right about reading/recovering 50% sectors of I have. Tried two times and arriving to the same result. Suspected a bad sectors is causing the hang. Managed to salvage about 140GB of data out of 396GB of original data.

(4)This is when I take apart the external enclose and plug the bare-bone drive into my SATA slot. The system recognizes the drive now as an internal drive ST3000DM01, not a usb external drive.

(5)Used TestDisk to create an image of the NTFS partition found and put it onto the other working hard drive. The image is a .dd file and it holds 396GB, pretty sure I have around 300-ish GB of data on this disk so I am convinced that the image produced is the complete hard drive image.

(6)Using SeaTools (by Seagate) for Windows, the drive failed all tests even after the Fix->All Long, it suggested using DOS version of SeaTools to look into the LBAs and attempt to fix the bad sector. Strangely, under the DOS version the drive passed all tests with no bad sectors. Not even passed with repair, just passed without errors. Maybe the difference is due to Intel RAID Controller vs. just plain Intel ICH8/9/10 controller. I have a RAID 0 configuration, no RAID on this drive because it was on a USB and the usb controller is different from RAID.

(6)Because PhotoRec couldn't get pass a certain sector due to some unknown reason, I decided to low-level format this drive under DOS using SeaTools. The Full erase process took 14 hours. After that I formatted the entire drive in Windows. Used the Check disk tool, found no sector errors. Used SeaTools, the drive failed the self-short test but passed short and long generic tests with 3 passes, so funky results. Seems to rule out my bad-sector theory but hey, who knows.

--------------------------------------------NOW HERE IS THE QUESTION (?)----------------------------------------------------
Actually, it all boils down to one questions: How do I restore the disk image file .dd to my Seagate hard drive? What are the steps?

Couldn't find the steps anywhere. For TestDisk, Is the definition of image file different from what i think it is?

This is my first time trying to recover data using TestDisk, any help is appreciated.

User avatar
Fiona
Posts: 2835
Joined: 18 Feb 2012, 17:19
Location: Ludwigsburg/Stuttgart - Germany

Re: How to restore .dd disk image?

#2 Post by Fiona »

Are you able to mount your image in testdisk and list your data?
http://www.cgsecurity.org/wiki/Media_Image
Run your command prompt as an administrator.
Go to Start.
Write cmd in search programs and files.
Press both, the Ctrl-key and Shift and press enter.
Confirm to proceed your command prompt as administrator.
Type cd (change directory) and space.
Copy your path to your image.dd in your command prompt and press enter.
Now, you can mount your image as described in the link above.
In TestDisk;
Confirm through until you see the menu Analyse.
Don't confirm at Analyse but Advanced.
Your partition should displayed correctly, if not or Unknown, go to type and choose your file system NTFS.
Confirm at Boot with enter also.
If a menu list is available, please check it and hit enter.
Do you see your data or an error message?
If no menu list is available and your boot sector and it's backup are bad;
Highlight Rebuild BS and hit Enter.
Rebuild your BS will be in progress.
Normally, it takes some minutes.
If it's finished, please post the infos or upload a screen.
If you see a menu List, please highlight it and press enter.
Please let me know, do you see your data or an error message.
To get back to the previous screen, easily press q for Quit.

If your data are listed, please copy them back to your disk.
At the bottom of the screen, you'll find all the commands.

andrewclam
Posts: 3
Joined: 07 Mar 2012, 21:29

Re: How to restore .dd disk image?

#3 Post by andrewclam »

Fiona wrote: In TestDisk;
Confirm through until you see the menu Analyse.
Don't confirm at Analyse but Advanced.
Your partition should displayed correctly, if not or Unknown, go to type and choose your file system NTFS.
Confirm at Boot with enter also.
If a menu list is available, please check it and hit enter.
Do you see your data or an error message?
If no menu list is available and your boot sector and it's backup are bad;
Highlight Rebuild BS and hit Enter.
Rebuild your BS will be in progress.
Normally, it takes some minutes.
If it's finished, please post the infos or upload a screen.
If you see a menu List, please highlight it and press enter.
Please let me know, do you see your data or an error message.
To get back to the previous screen, easily press q for Quit.

If your data are listed, please copy them back to your disk.
At the bottom of the screen, you'll find all the commands.
In TestDisk, when entered [advanced] it said [no partition available], I don't know how to go to type - > choose file system -> NTFS. There isn't an option for File system type.

I am using 6.13 by the way.

andrewclam
Posts: 3
Joined: 07 Mar 2012, 21:29

Re: How to restore .dd disk image?

#4 Post by andrewclam »

An update to this issue:

I wasn't able to use testdisk.exe to restore the disk image onto my disk yet; However, I did manage to mount the image using photorec now. I am using the photorec to try once more to recover files from this image, hopefully I can recover most of the data. I hope it won't stop at the midway again like with the bad drive. This time photorec should be reading image file from a good hard drive, not the Seagate drive that had the problems.

I wonder if the image-copy of a bad drive will carry over the "glitches" of the bad drive, I assume if the photorec encounter corrupted copies, it will skip the bytes and move on.

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