dd if=/dev/zero of=myfsys bs=512M count=1 # creating a 512M zeros file
mke2fs myfilesys # creating a file system out of the file

mount myfilesys /mnt -o loop=/dev/loop0 # mounting it as a loop device

mkdir /mnt/point1 # creating a mount point
mount /dev/loop0 /mnt/point1 # mounting 

df /mnt/point1/ # its alive!

# results with:
# Filesystem           1K-blocks      Used Available Use% Mounted on
# /dev/loop0              516040       400    489428   1% /mnt/point1

Basic file system manipulation in Linux (some commands require sudo).

Creating a new filesystem within a file

Bash, linux

Bash