I'm trying to recover data after formatting my hdd. I installed ddrescue-gui and performed the following tasks:

  1. Select source (formatted hdd), no log, destination (img file inside separate hdd) and set to fastest recovery then click start

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  1. Went into Computer and found that the source drive was now unmounted. So I went into Disks to see if I could mount it, but could not because it was now two loop devices:

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  1. So I tried various terminal commands to no avail, getting errors such as:

    sudo mount -t ntfs "/media/user/e3cfeead-6e65-4af5-beb8-bbfa12fbdaa5/1tb.img" /dev/loop0

    NTFS signature is missing. Failed to mount '/dev/loop2': Invalid argument The device '/dev/loop2' doesn't seem to have a valid NTFS. Maybe the wrong device is used? Or the whole disk instead of a partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?

  2. The file is currently sitting on a separate hdd and the 1tb hdd I'm trying to recover is inaccessible:

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I'm new to this whole scene so I'm really confused at the moment. No idea why my drive got unmounted, converted to a "loop device" (whatever that is) and why I can't just get my data and then mount my device again. Is there a correct way of going about this?

I checked the official Launchpad GUI site but I didn't find any tutorials or guides or anything useful.

2 Answers 2


You have a image of a filesystem (1tb.img) inside a filesystem (/dev/sdf of /media/user/e...aa5).


sudo mount  "/media/user/e3cfeead-6e65-4af5-beb8-bbfa12fbdaa5/1tb.img" /mnt


sudo mount -o loop "/media/user/e3cfeead-6e65-4af5-beb8-bbfa12fbdaa5/1tb.img" /mnt
  1. mount should find filesystem type.
  2. add -r after mount to mount your image read only.


  1. use /mnt (not /media/user/XXYY) as mount point.
  2. sudo mount -o ro,loop -t ntfs /media/user/e3../1tb.img /mnt
  3. try fstyp (or fstype) to check which filesystem

    fstype /media/user/e3cfeead-6e65-4af5-beb8-bbfa12fbdaa5/1tb.img
  4. analyse file using ... file

    file /media/user/e3cfeead-6e65-4af5-beb8-bbfa12fbdaa5/1tb.img
  • both commands: sudo mount "/media/user/e3cfeead-6e65-4af5-beb8-bbfa12fbdaa5/1tb.img" "/media/user/B5C4-62C3" or sudo mount -o loop "/media/user/e3cfeead-6e65-4af5-beb8-bbfa12fbdaa5/1tb.img" "/media/user/B5C4-62C3" result: mount: block device /media/user/e3cfeead-6e65-4af5-beb8-bbfa12fbdaa5/1tb.img is write-protected, mounting read-only mount: you must specify the filesystem type with -r: mount: you must specify the filesystem type with -t ntfs: NTFS signature is missing. Failed to mount '/dev/loop2': Invalid argument The device '/dev/loop2' doesn't seem to have a...
    – Hooli
    Feb 15, 2016 at 13:35
  • @Hooli see my edit
    – Archemar
    Feb 15, 2016 at 16:18
  • for #1 and #2 I get the same errors mentioned above, for #3 I get fstype: command not found, for #4 I get /media/user/e3cfeead-6e65-4af5-beb8-bbfa12fbdaa5/1tb.img: x86 boot sector
    – Hooli
    Feb 15, 2016 at 16:20

First, you should use log with ddrescue.

Second, your image is going to be an image of whole drive which means you have to know where partitions starts.

| MBR PT  | part1     | part2     | partN     |

Use file <image> to gen information on your image. Should give you something more like: (that's my memory stick; you get the idea)

You can also use fdisk <image> or cfdisk <image>. All they should show you geometry of your disk (in image) so you can find out where is beginning of partition to mount.

$ file sda.img
sda.img: MBR boot sector; partition 1 : ID=0xc, active, start-CHS (0x0,32,33), end-CHS (0x3ff,254,63), startsector 2048, 30308352 sectors

So proper mount line would be:

# mount -tvfat -oloop,offset=$((2048*512)) sda.img /mnt/sda1

as you have to inform mount where the actual partition starts - with offset option which is byte offset. That's why there is offset=$(2048*512)) as file/fdisk/cfdisk shows it in sectors (although you can change units in fdisk/cfdisk).

Your commands will be more like

mkdir /mnt/image
sudo mount -o ro,loop,offset=YOUR_OFFSET -t ntfs /path/to/1tb.img /mnt/image

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