Re: Easiest Way to Mount an Image File

[Reco <recoverym4n@gmail.com>]

	Hi.

On Sun, 18 Dec 2016 08:41:01 -0600
"Martin McCormick" <martin.m@suddenlink.net> wrote:

> The following command works:
> 
> sudo losetup /dev/loop0 /home/pgmaudio/2016-11-25-raspbian-jessie-lite.img
> 
> When one does
> 
> fdisk -l /dev/loop0 the result is sensable:
> 
>       Device Boot      Start         End      Blocks   Id  System
> /dev/loop0p1            8192      137215       64512    c  W95 FAT32 (LBA)
> /dev/loop0p2          137216     2715647     1289216   83  Linux

You could do the same without being root:

/sbin/fdisk -l /home/pgmaudio/2016-11-25-raspbian-jessie-lite.img

Or, better yet:

/sbin/parted /home/pgmaudio/2016-11-25-raspbian-jessie-lite.img print


> If you try something like 
> 
> sudo mount /dev/loop0 p2 /mnt
> 
> The report is that it doesn't exist and ls /dev/loop0* only shows
> the original loop0 loopback device. I looked through all of /dev
> such as /dev/mapper and there seems to be nothing else pertaining
> to loop0 so what am I missing?

You're missing two things:

1) While losetup 'cooks' you a block device from the file, it does not
expose underlying partitions. What you need is:

sudo kpartx -a /home/pgmaudio/2016-11-25-raspbian-jessie-lite.img

Look for devices created in /dev/mapper, don't forget to run afterward:

sudo kpartx -d /home/pgmaudio/2016-11-25-raspbian-jessie-lite.img


2) You don't need to invoke losetup at all to mount a filesystem inside
a file. mount(1) is clever enough to do it on behalf of you:

sudo mount -o offset=$((512*8192)) \
 /home/pgmaudio/2016-11-25-raspbian-jessie-lite.img <mountpoint1>

sudo mount -o offset=$((512*137216)) \
 /home/pgmaudio/2016-11-25-raspbian-jessie-lite.img <mountpoint2>

Reco