Question Is there a way to backup/clone a partition without wiping data on the destination drive?

[ddresmew]

Hi everyone, I've been trying for days, and out of frustration I thought I should ask for advice from you guys.
Here's my issue: I have this external 500GB HDD that contains very important files. It's formatted to NTFS and has been failing to read/write, shows some bad sectors (forgot how many and I can post a detailed SMART analysis if needed). Sometimes it is read but not for long, and because of that I have been able to back up a small amount of the files.
I have another external 4TB HDD which can be used as a destination for the files on the older hard drive or the image of it. It's formatted to exFAT and already has files on it that I would rather not delete (some of which are, as I mentioned, part of the backed-up data). I would rather not format this drive and I don't have any other alternative. Because it's exFAT I can't resize it but I wish I could...

My question is: is there a way to make an image of the failing hard drive (using dd or testdisk or some similar tool) WITHOUT wiping the data on the other hard drive? Thanks in advance.

PS: I successfully made a list of files on this drive so I can re-download the files that I won't be able to retrieve, but the files I really need to backup are private (pictures mainly).

 

[Misgar]

I think your best course of action would be to hand the drive over to a professional drive recovery agency and fork out $300 to $800. That's the price you have to pay for failing to make backups of all important files.

If the hard disk is developing bad blocks, many of your "important" files may already be lost. A professional agency can image the disk using specialist tools which ignore CRC errors and might be able to recover more files than you can. They may strip the platters out of your drive in a clean room and install them in a donor drive to aid recovery. All this costs money.

Don't compound the damage by struggling to pull a few more files off the disk. Each time you power up the drive, you risk degrading data integrity still further.

 

[drea.drechsler]

....
My question is: is there a way to make an image of the failing hard drive (using dd or testdisk or some similar tool) WITHOUT wiping the data on the other hard drive? Thanks in advance.
....

Why do you want to make an image of the failing drive, vs. just copying the files off into a backup using something like Macrium Reflect?

But for what you're asking I'd use PartitionMaster but only because I'm familiar with it. One way to do this is to image the partition vs. the drive. I'd first resize the existing partion on the destination disk to make room or "unformatted" space. Then copy the data partition from the source disk into the unformatted space on the destination disk. PM lets you resize the destination partition to fit available space so long as the data will fit. You'll be left with two partitions on the destination disk, each with it's own drive letter.

I think the free trial version of PM lets you do all these operations.

However this will likely fail if there are hardware level read errors due to a failing disk, as would most any imaging software although I'm not familiar with "dd" and "testdisk" to know what they are capable of. In such cases you'd need to use a recovery service, as previously mentioned, to get what they can.

 

[TerryLaze]

Sometimes it is read but not for long,

...
...

My question is: is there a way to make an image of the failing hard drive (using dd or testdisk or some similar tool) WITHOUT wiping the data on the other hard drive? Thanks in advance.

Yes dd has an if (input file) and of (output file) command and both can be files or devices.
HDDrawCopy is a free graphical interface for it and you can also save the image with compression by selecting the .imgc extension in the file save dialog.
But if the source disk doesn't stay connected for long enough to take the whole image then there is no sense in doing it.

I would disassemble the external case and see if it stays connected as an internal drive.

(Also take a backup of important files of the 4Tb disk to a different disk, I already see you back here in a few years asking the same things about the 4Tb disk)

 

[fzabkar]

The best cloning tool is HDDSuperClone. It is now freeware, and has also been ported to OpenSuperClone. Its author has provided a bootable ISO and a GUI.

This multipass tool will clone the easy sectors on the first pass and then try for the more difficult sectors on subsequent passes. It can clone your 500GB HDD to a 500GB image file on your 4TB HDD. You can then use a data recovery tool such as DMDE to recover your files from the image. Alternatively, if the file system in the image is intact, you can mount the image with OSFMount (freeware) and copy and paste the files as you would in Windows File Explorer.

Note that other cloning tools will thrash a bad sector until the retries are exhausted. This will accelerate the complete failure of a failing drive. HDDSuperClone will disable retries and skip over any bad areas until the final passes.