dmg

Create a virtual hard drive volume within a file in Linux

If you are not familiar with the concept of virtual hard drive volumes, sometimes called file containers, they are basically regular looking files that can be used by your computer as if they were real hard drives. So for example you could have a file called MyDrive.img on your computer and with a few quick actions it would appear as though you had just plugged in an external USB stick or hard drive into your computer.