[SOLVED] Mounting a single fat32 partition inside a full disc image

mtb · 12-19-2009, 02:47 PM

I have recovered a whole dying hard drive using the command ddrescue, only 8192 byte out of 4.3 gigabyte are unreadable.

I have used the command (gnu) ddrescue /dev/sdb DiskImage.img

But unfortunatly this way i have a full-disk image that is not mountable... ( or at least i don't know how to mount it ), and the disk doesn't seem to work anymore that good... ( crack crack crack... ).

To see the partitions inside the "big" file, i have used fdisk -l, and damn there is only one partition, but how can i mount the content???

Code:

$ fdisk -l DiskImage.img
 
Si devono impostare cilindri.
È possibile effettuare questa operazione dal menu delle funzioni supplementari.

Disco DiscoF.img: 0 MB, 0 byte
255 heads, 63 sectors/track, 0 cylinders
Units = cilindri of 16065 * 512 = 8225280 bytes
Disk identifier: 0x3cfc3cfb

Dispositivo Boot      Start         End      Blocks   Id  System
DiscoF.img1   *           1         523     4200966    b  W95 FAT32

I know i could use photorec foremost or similar software, but since the disc image is almost perfect, i would be able to preserve file names, paths and dates...

The last idea would be to mount it as a full-drive image with Virtualbox... But transferring data would be quite annoying.

Thank you in advance.

linus72 · 12-19-2009, 03:00 PM

maybe kpartx can be used?

kpartx can mount partitioned virtual hard drives,etc
http://panoskrt.wordpress.com/2009/0...in-image-file/

http://www.forensicswiki.org/wiki/Mounting_Disk_Images

hope that helps some?

mtb · 12-19-2009, 03:07 PM

Great!!!

Thank you!

Unfortunatly kpartx for ubuntu 8.04 seems broken, but i'm launching the laptop with 9.04 and i hope it will work!

linus72 · 12-19-2009, 03:09 PM

I used it in 9.04
it works for me

course I'm just trying to mount partitioned qemu img's

mtb · 12-19-2009, 03:19 PM

Perfect! Thank you again.

By the way, works after a reboot even with 8.04 lts.

linus72 · 12-19-2009, 03:23 PM

what works after reboot?
did you fix it already?
OH- you mean kpartx?

mtb · 12-19-2009, 04:57 PM

kpartx avaible from ubuntu 8.04 repositories works after reboot.

I did everything i needed!

linus72 · 12-19-2009, 05:56 PM

then mark the thread as solved!
go to your first post, select thread tools/mark as solved from right hand corner^

so it worked OK or what?
If you wanna help out others who read this
Please explain what you did?

mtb · 12-20-2009, 02:20 AM

You're right:

I did as root:

Code:

#kpartx -a DiskImage.img
gpt: 0 slices
dos: 4 slices

in order to  add partition devmappings

#kpartx -l DiskImage.img
gpt: 0 slices
dos: 4 slices
loop0p1 : 0 8401932 /dev/loop0 63

And i copied the loop name ( loop1p1 )

Then i did:

mount -o ro /dev/mapper/loop1p1 /mnt/recovery

And copied the whole content from /mnt/recovery

It worked perfectly.

After i removed the loop0p1 device with

Code:

#kpartx -d DiskImage.img
gpt: 0 slices
dos: 4 slices
loop deleted : /dev/loop0

linus72 · 12-20-2009, 04:33 AM

Your the Man

Linux rocks huh?

David the H. · 12-20-2009, 06:39 AM

For the record, to manually mount a partition inside a disk image:

First use...

Code:

fdisk -lu diskimage.iso

...to get the block size and starting block number of the partition you want to mount.

Then mount the device with loopback and an offset option equal to blocksize*startingblock.

You can use bash's built-in arithmetic function to calculate it for you.

If, for example, the blocksize is 512, and the starting block is 40890...

Code:

mount -t auto -o loop,offset=$((40890*512)) /path/to/diskimage.iso /mnt/mountpoint

There may be other ways to do it as well, but this is what I've used in the past.