Mounting a file as a filesystem

file2fs.sh

# Create a new file
dd if=/dev/zero of=my_fs bs=1M count=1024
Or 
truncate -s 30M my_fs

# Check if the device is not already in use before using it 
sudo losetup /dev/loop0
sudo losetup /dev/loop0 my_fs 

# Make a file system and mount it
sudo mkfs -t ext3 -m 1 -v /dev/loop0
sudo mount -t ext3 /dev/loop0 /mnt/new

# Done. Now let tear it down !!


sudo unmount /mnt/new
sudo losetup -d /dev/loop0
# Gone !!