This question already has an answer here:

While Trying to mount a disk image in Raw(dd) format using the following command

mount  nps-2010-emails.dd /media/manu/

I get the following error message

mount: you must specify the filesystem type

I know that using -t we can specify the file system but what is the terminology for a RAW (dd) file, which can pe passed as an argument to the mount command. If my method to mount this file system is wrong please help me out in doing the same.

On typing the command file -s nps-2010-emails.dd

The output is as follows:

nps-2010-emails.dd: x86 boot sector; partition 1: ID=0xb, starthead 254, startsector 1, 20479 sectors, extended partition table (last)\011, code offset 0x0

marked as duplicate by strugee, derobert, jasonwryan, slm, Thomas Nyman Jun 14 '14 at 12:10

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.


The image you have is the image of an entire disk including things like partition tables and other things outside of the file system that you would like to mount inside it. You likely have at least one partition inside that raw blob. Mount is telling you it can't figure out what file system it is because it is starting to read the raw blob at the beginning and finding things that are not part of a file system at all.

In order to mount the file system, you need to figure out where the file system is. This answer on Ask Ubuntu has some details about how you can calculate where the partition starts in the image and then use that value to create a loop device that starts at that offset. If you want to simplify even further, once you have found the right offset value you can skip the loop device setup and pass the offset value directly to mount using mount -o offset=<offset in bytes>.


Try this:

mount -t auto -o loop nps-2010-emails.dd /media/manu/
  • 1
    I still get the message : mount: you must specify the filesystem type ,still could you please explain what it is that you have suggested me to do. – spaceman_spiff Jun 14 '14 at 7:48
  • notice x86 boot sector. this indicates that he has a full disk image, which will require losetup to access... which makes it a dupe. – strugee Jun 14 '14 at 9:01
  • @strugee This information was not available when I wrote my answer. – Hauke Laging Jun 14 '14 at 16:35
  • @HaukeLaging ah, that makes a lot more sense. in that case, it was a good guess. – strugee Jun 14 '14 at 23:03

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