Also, specify the desired location and name for the file. To create virtual hard-drives for the virtual machines, run 'qemu-img create /PATH/AND/FILENAME SIZE' where 'SIZE' is the desired virtual hard-drive size (3G is 3-gigabytes, 512M = 512-megabytes, etc.). This article will discuss the basics of using Qemu, but not the networking. However, many users report difficulties with network support for the guest systems. Oracle's VBox supports x86-64 and x86 operating systems as guests while Qemu supports other architectures such as arm, mips, and more.
With Qemu, users can run a larger variety of virtual machines than VirtualBox. Qemu is another virtual machine application for Linux and an alternative to Oracle's VirtualBox.