I am trying to recover the data from an external HDD for a friend.

I am using Knoppix latest version booting it from USB.

I created an image (.img) using a tutorial for ddrescue, but now I have the copia.img file and can't mount it.

If I try to mount the terminal says:

mount: wrong fs type, bad option, bad superblock on .....

The drive was used to storage photos and does not contain any OS or similar.

If I run File command to the copia.img file it says:

DOS/MBR boot sector, code offset 0x52+2, OEM-ID "NTFS", Media descriptor 0xf8, sectors/track 63, heads 255, hidden sectors 63, dos <4.0 BootSector (0x80), FAT (1Y biy by descriptor);NTFS, sectors/track 63, sectors 1953520001, $MFT start cluster 21931768, $MFTMirror start cluster 477176, clusters/RecordSgement 2, clusters/index block 8, serial number 0d2c6a522c6a507b5; contains Microsoft Windows XP/Vista bootloader BOOTMGR

Also, if I run dmesg command it says:

enter image description here

Please can you please help me recovering it?

  • What does file copia.img say? What is the mount command you are using (I assume you are mounting through a loop device, but it's best if we can see exactly)?
    – dhag
    Feb 10, 2017 at 17:12
  • @dhag i use "mount -o loop,ro copia.img mountpoint but it says:mount: wrong fs type, bad option, bad superblock on .....
    – jfim88
    Feb 10, 2017 at 17:35
  • What does file copia.img say?
    – dhag
    Feb 10, 2017 at 17:46
  • i don't understand what you are asking me...sorry i'm very noob in Linux @dhag
    – jfim88
    Feb 10, 2017 at 17:51
  • It means "please run the command file copia.img in a terminal and edit your question to add this and its output".
    – dhag
    Feb 10, 2017 at 18:02

1 Answer 1


From the output of your call to file, it appears that your file is an image of a whole block device, containing several partitions, rather than a single filesystem. This explains why mount could not mount it: that command supports mounting single filesystems.

To mount a filesystem that is within a disk image, you have to:

  1. run fdisk -l on the image to find the file system offsets;
  2. compute <offset> * <block size> to get the offset in bytes;
  3. create a loop device from the file at that offset;
  4. mount using that loop device explicitly.

I'm taking excerpts from https://web.archive.org/web/20170917154947/http://madduck.net/blog/2006.10.20:loop-mounting-partitions-from-a-disk-image/ which has complete instructions; this could look like:

$ /sbin/fdisk -lu disk.img
Units = sectors of 1 * 512 = 512 bytes

      Device Boot      Start         End      Blocks   Id  System
disk.imgp7        10860003    68372639    28756318+  83  Linux

# losetup /dev/loop0 disk.img -o $((10860003 * 512))
# file -s /dev/loop0
/dev/loop0: Linux rev 1.0 ext3 filesystem data
# mount /dev/loop0 /mnt
# umount /mnt
# losetup -d /dev/loop0

That same blog post indicates that a newer package named "kpartx" may be able to automate the computation.

  • Thanks! I am trying but it does not run. fdisk shows "Unidades: sectores de 1 * 512 = 512 bytes", and /media/sdf1/Copia/copia.img starts at 539915109, but when I try to run losetup /dev/loop0 /media/sdf1/Copia/copia.img -o $((539915109 * 512)) I get "losetup: /media/sdf1/Copia/copia.img: error al configurar dispositivo de bucle: Dispositivo o recurso ocupado" (Device or resource occupied)
    – jfim88
    Feb 10, 2017 at 19:21
  • i can see that there are 4 partitions but when i try the losetup command it says that device is occuped
    – jfim88
    Feb 10, 2017 at 20:56
  • The device loop0 may have been created by your first attempt; either release it, or try with e.g. loop1.
    – dhag
    Feb 10, 2017 at 21:29
  • Seems that now runs. When tipe command File -s /dev/loop0 it shows "data". But when i try mount /dev/loop0 /mnt it shows an error. Says that codepage or auxiliar program lacks or another error. Incorrect file system type, incorrect option...
    – jfim88
    Feb 10, 2017 at 21:58
  • I just executed the command parted and it only shows 1 partition. Start 0B and ends 1000202241023B in NTFS.
    – jfim88
    Feb 10, 2017 at 22:13

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