mounting whole disk img

[carlinuxlearner]

This might be in the wrong forum. I don't know, I really had no idea where to put it, so please move it if necessary.

What I did:
Used ddrescue to clone a 500GB hard drive that was failing (read errors, wouldn't boot, etc...)
The command I used to do it was:

sudo ddrescue /dev/sdh /location/I/picked.img
Well it took it 2 days, but it finally got past all the errors and completed.

What I'm trying to do:
Now that I have a copy of it all, I want to mount the image and access the files.

What's not working?
When I enter:

sudo mount picked.img /where/I/want/to/mount/it/
it says: "mount: /location/I/picked.img is not a block device (maybe try `-o loop'?)"

And when I try
sudo mount -o loop picked.img /where/I/want/to/mount/it/
it says: "mount: you must specify the filesystem type"

Well the disk was partitioned with NTFS, so I try
sudo mount -t ntfs -o loop picked.img where/I/want/to/mount/it/

And the result is:

NTFS signature is missing.
Failed to mount '/dev/loop0': Invalid argument
The device '/dev/loop0' 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?



SOooo, what's wrong here? It seems to me I'm trying to mount it the wrong way, since it's an image of the whole disk, and not just one partition. And if that is the problem, then how do I mount it?

[sisco311]

To mount a partition inside the disk image you need to calculate the offset of where the partition starts.


parted picked.img



GNU Parted 2.3
Using picked.img
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) unit
Unit? [compact]? B
(parted) print

The output should look something like:

Model: ATA ST3160815AS (scsi)
Disk /dev/sda: 160041885696B
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
1 32256B 10733990399B 10733958144B primary ext4
2 10733990400B 21500881919B 10766891520B primary ext3
3 21500881920B 158961761279B 137460879360B primary ext4
4 158961761280B 160039272959B 1077511680B primary linux-swap(v1)


type q to exit from parted.

Now to mount a partition, you have to run something like:

sudo mount -o loop,offset=32256 picked.img mount/point

[carlinuxlearner]

You, are a genius! :D

Not only did it solve my problem, but I learned something new while I was at it! It worked perfectly. Thank you!

[sisco311]

You're welcome!

[blueridgedog]

To mount a partition inside the disk image you need to calculate the offset of where the partition starts.


Excellent and succinct help!

[mips]

Well it took it 2 days, but it finally got past all the errors and completed.


In future rather try safecopy (https://sourceforge.net/projects/safecopy/). I find it MUCH faster than ddrescue when it starts encountering bad sectors.

Here is a nice post on how to extract & mount partitions from image files https://sourceforge.net/projects/safecopy/forums/forum/472935/topic/3495567

[dcstar]

In future rather try safecopy (https://sourceforge.net/projects/safecopy/). I find it MUCH faster than ddrescue when it starts encountering bad sectors.


It is better to also tell people that the safecopy package is in the repositories. There is no need to download and manually install.

[mips]

It is better to also tell people that the safecopy package is in the repositories. There is no need to download and manually install.

The link to sourceforge was for reference only.