Fwd: mount foo.img problem
On Sat, Feb 7, 2009 at 11:52 PM, Aneurin Price <aneurin.price@gmail.com> wrote:
> On Sat, Feb 7, 2009 at 10:24 PM, Thomas H. George <lists@tomgeorge.info> wrote:
>> On Sat, Feb 07, 2009 at 03:28:20PM -0600, Boyd Stephen Smith Jr. wrote:
>>> On Saturday 07 February 2009 13:37:46 Thomas H. George wrote:
>>> > On Sat, Feb 07, 2009 at 10:44:47AM -0600, Boyd Stephen Smith Jr. wrote:
>>> > > On Saturday 07 February 2009 10:31:17 Thomas H. George wrote:
>>> > > > What must I do to be able to mount this image file?
>>> > > Could you run "file debxo-awesome.ext3.img" can provide the output?
>>> > dragon:/data/olpc# file debxo-awesome.ext3.img
>>> > debxo-awesome.ext3.img: x86 boot sector; partition 1: ID=0x83, active,
>>> > starthead 1, startsector 32, 3848160 sectors dragon:/data/olpc# exit
>>>
>>> It looks like it is a whole-disk image -- the first part of it appears to be
>>> an MBR. You'll need to use some loopback parameters to skip the MBR and
>>> partition table. I think you only need to skip 512 bytes... could you try:
>>> tail -c +513 debxo-awesome.ext3.img | file -
>>> and see if that reports that it found an ext3 filesystem.
>>
>>
>> Script started on Sat 07 Feb 2009 05:14:12 PM EST
>> dragon:/data/olpc# tail -c +513 debxo-awesome.ext3.img | file -
>> /dev/stdin: GRand Unified Bootloader stage1_5 version 3.2, identifier 0x2, GRUB version 0.97, configuration file \377
>> dragon:/data/olpc# exit
>>
>> Script done on Sat 07 Feb 2009 05:15:09 PM EST
>>
>> So I tried
>>
>>
>> Script started on Sat 07 Feb 2009 05:20:59 PM EST
>> dragon:/data/olpc# mount -o loop.offset=512 -t ext3 debxo-awesome.ext3.img /medi a/sdloop
>> mount: /data/olpc/debxo-awesome.ext3.img is not a block device (maybe try `-o loop'?)
>> dragon:/data/olpc# exit
>>
>> which seemed to be what the Debian Reference suggested but I guess this
>> is not quite right.
>>
>> Script done on Sat 07 Feb 2009 05:21:57 PM EST
>>>
>>> > The image was meant to be transfered to a USB device but the
>>> > instructions said that if the device was less than 2 Gb it could be loop
>>> > mounted as ext3 in order to copy the guts of the image to a smaller USB
>>> > device.
>>>
>>> It can be, but in this case it's not as simple as just using the loop mount
>>> option, unfortunately. You'll probably need just the additional offset
>>> option. Once we find the offset, things should be "easy"; although, after you
>>> move the files over, you'll also want to dd the MBR over as well.
>
> You could try a slightly more heavy-handed approach:
>
> for ((i=0 ; $i < 10000 ; i=$i + 1)) ; do
> mount -o loop,offset=$(($i * 512)) debxo-awesome.ext3.img
> /media/sdloop && break
> done
>
> You might even be able to use fdisk on the image to get some more information,
> but I don't know about that.
>
Actually, give this a go:
mount -o loop,offset=16384 debxo-awesome.ext3.img /media/sdloop
Reply to: