how to mount .img file
 

hi,
i want to install arch-live-usb from harddisk instead of usb ;but i have occured a problem :

# file arch-live-usb_201105070115.img arch-live-usb_201105070115.img: x86 boot sector; partition 1: ID=0x83, starthead 32, startsector 2048, 591872 sectors, extended partition table (last)\011, code offset 0x0

from ID=0x83 we it's ext3

# mount -t ext3 -o loop arch-live-usb_201105070115.img /mnt/
mount: wrong fs type, bad option, bad superblock on /dev/loop0,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so

# dmesg | tail
[13986.478722] VFS: Can't find ext3 filesystem on dev loop0.

# losetup -f arch-live-usb_201105070115.img
# losetup -a
/dev/loop0: [0809]:262025 (/home/sense/software/test/arch-live-usb_201105070115.img)
# mount /dev/loop0 /mnt/
mount: you must specify the filesystem type
# mount -t ext3 /dev/loop0 /mnt/
mount: wrong fs type, bad option, bad superblock on /dev/loop0,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so
# dmesg | tail
[13986.478722] VFS: Can't find ext3 filesystem on dev loop0.

thank you.

.img files are often compressed with gzip or cpio or both. To gather a distro into one file needs cpio or tar, cpio being preferred as it offers some compression.

run file on it.

The problem is that the .img files are not images of a partition, but of a whole disk. That means they start with a bootloader and a partition table. You have to find out the offset of the partition and mount it with the offset option of mount.
If you do ait will show you the block-size and the start-block of the partition. You can use that to calculate the offset.
For example, I have an image of a bootable stick with a 4GB FAT32 partition. The output of the fdisk command isSo I have a block-size of 512 bytes and the start-block is 128. The offset is 512 * 128 = 65536.
So the mount command would be

thank you

that is the info on my computer:
# fdisk -l arch-live-usb_201105070115.img
You must set cylinders.
You can do this from the extra functions menu.

Disk arch-live-usb_201105070115.img: 0 MB, 0 bytes
248 heads, 19 sectors/track, 0 cylinders
Units = cylinders of 4712 * 512 = 2412544 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xff978785

Device Boot Start End Blocks Id System
arch-live-usb_201105070115.img1 1 127 295936 83 Linux
Partition 1 has different physical/logical beginnings (non-Linux?):
phys=(0, 32, 33) logical=(0, 107, 16)
Partition 1 has different physical/logical endings:
phys=(36, 247, 19) logical=(126, 10, 18)

# mount -o loop,offset=512 arch-live-usb_201105070115.img /mnt
mount: you must specify the filesystem type
# mount -t ext3 -o loop,offset=512 arch-live-usb_201105070115.img /mnt
mount: wrong fs type, bad option, bad superblock on /dev/loop0,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so

# dmesg |tail
VFS: Can't find ext3 filesystem on dev loop0.

now i don't know how to do

OK, the the image has a format unknown to me. Sorry, I can't help you with that.

Thank you for the same

You do not know for sure that the partition is formatted as ext3

The partition type of 0x83 just means "linux", and although that can mean ext3, it ain't necessarily so.

Try reading this post by David the H. where he is using the -t auto option to mount, to mount a partition within an image.

thank you very much!

it's work good now

# fdisk -lu arch-live-usb_201105070115.img
You must set cylinders.
You can do this from the extra functions menu.

Disk arch-live-usb_201105070115.img: 0 MB, 0 bytes
248 heads, 19 sectors/track, 0 cylinders, total 0 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xff978785

Device Boot Start End Blocks Id System
arch-live-usb_201105070115.img1 2048 593919 295936 83 Linux
Partition 1 has different physical/logical beginnings (non-Linux?):
phys=(0, 32, 33) logical=(0, 107, 16)
Partition 1 has different physical/logical endings:
phys=(36, 247, 19) logical=(126, 10, 18)

# mount -t auto -o loop,offset=$((2048*512)) arch-live-usb_201105070115.img /mnt/

Many, many thanks. All work perfectly.

Moderator response
 

@gopyan
Please do not resurrect necro threads without adding constructive information to thread via posts. If you wish to honor the help then just press 'Did you find this post helpful?' Yes to find the post helpful. Or you can give Rep by pressing the scales icon under the members profile.

I just wanted to thank you. It just solved my problem.

Yakooza, hello and welcome to LQ.

Glad it still works.
Be sure you watch the age of the threads. A lot can change in 7 years.

Thank you for your welcome.
Yes, I have noticed that but I had to thank him :)

Thanks

The chances are the poster in question doesn't even post on here any more. So, I'm afraid to say that, like this post, your post added noise, not signal.

Hehehe - Check the badge. Nothing like a good moderator spank to sharpen you up.

Many years ago I had made an image file for backup purpose from my entirely 2.0 GByte pendrive using the 'dd' bash command. The pendrive was bootable, It had a bootable live-Devian version on it. Yesterday I was able to mount the image file by simply using the "mount" command without any offset at all and it worked pretty well. The other option that I had to access the image file content was to use again the 'dd' command to restore the image back to the original pendrive, but since the original pendrive has new content now, this option was discarded and I mounted the image file using:

user~$ sudo mount -o loop /path/traveldata2gb.img /mnt/tmp [enter]

My conclusion then is that apparently the "offset" statement (computed by using fdisk information on the image file) is not always mandatory.