Linux Shell Scripting Cookbook - Third Edition

Creating partitions inside loopback images

Suppose we want to create a loopback file, partition it, and finally mount a sub-partition. In this case, we cannot use mount -o loop. We must manually set up the device and mount the partitions in it.

To partition a file of zeros:

    # losetup /dev/loop1 loopback.img
    # fdisk /dev/loop1

fdisk is a standard partitioning tool on Linux systems. A very concise tutorial on creating partitions using fdisk is available at http://www.tldp.org/HOWTO/Partition/fdisk_partitioning.html (make sure to use /dev/loop1 instead of /dev/hdb in this tutorial).

Create partitions in loopback.img and mount the first partition:

    # losetup -o 32256 /dev/loop2 loopback.img

Here, /dev/loop2 represents the first partition, ...