Your objectives are to install VirtualBox on your Debian server, and then install NixOS as a virtual server inside of VirtualBox. First, install VirtualBox. You can install the full VirtualBox from VirtualBox.org, or you can install it from a Debian repository. If you are running without a windowing environment, you will need to do a headless VirtualBox set-up, which can be somewhat challenging — you might want to check the VirtualBox forums if you go this route.
Next, pull down an ISO of NixOS from here; I would suggest "latest-iso-graphical-x86_64-linux", but "latest-iso-minimal-x86_64-linux" is certainly viable, and is smaller. (Virtualbox will be a lot happier if you make sure that the filename ends in ".iso".)
Now use the "create a new machine" option on VirtualBox; use a VDI (not a real partition) and this disk image doesn't need to be very large (30 gigabytes is more than sufficient). Give the machine only one processor and 1 gigabyte of memory. Make sure that your new virtual server's network device is visible to the lab (do not use an internal-only or NAT configuration). See the VirtualBox networking documentation for more information about your choices. Configuration of NixOS is a bit more challenging than many Linux installations since you will have to set up the disk space manually, much as you might to do for Linux From Scratch. Once you have NixOS running, please do a "nix-env -u" to update the system.
As to the new virtual server's internal configuration, you don't have to install any graphical interface (indeed, the minimal doesn't offer anything other than command line by default), but you are welcome to do so if you like. For an ip number, please use your next IP number, (i.e., if your Debian box is using 192.168.26.50, then use 192.168.26.51 for this assignment.)
You might be amused to visit the "/nix/*" subdirectories.
A journal is due for this assignment. Make sure that you document in your journal all of the steps that you went through, following the guidelines on the class home page.
Please turn in a printed copy of this assignment at the beginning of class on Tuesday, October 15.