What does dd if=/dev/zero of=storage_device.img bs=1M count=100 create?
dd if=/dev/zero of=storage_device.img bs=1M count=100
A 100 MiB zero-filled file that can act as a simulated storage device.
One hundred separate one-megabyte image files.
A mounted ext4 filesystem ready for file access.
A copy of storage_device.img written into /dev/zero.
storage_device.img
/dev/zero