Richard Bucker

Installing NixOS - Short Version

Posted at — Jan 22, 2015

I have been experimenting with NixOS for the last few weeks and every day I find some new reason to like it.

My first experiences were with the VirtualBox version. It was easy to use and the default configuration, with KDE, was pleasant even though I went directly to the Konsole and then with ssh. On the list of interesting features:

Today I installed sshd and started to consider doing a complete install from scratch or at least the closest thing to it. Not knowing how NixOS liked to be installed and that their own manual was a little sparse on the details I found this article that gave me a good head start. I suppose I could just leave the article at that, however, I want my own interpretation of the article in a more concise form; so here we go:
  • download the ISO image, in my case I did the minimal version [no X or desktop]
  • create a VM using VirtualBox and mount the ISO image on the VM’s CDROM (I configured it for 512M and 16GB disk)
  • boot the VM
  • run some commands and do some work
    • fdisk /dev/sda
    • press “o” to create a DOS partition
    • press “n, p, 1, ENTER, +2G, t, 82” to create the boot/swap partition
    • press “n, p, 2, ENTER, ENTER” to allocate the rest of the drive for NixOS
    • make the swap partition “mkswap -L swap /dev/sda1”
    • turn the swap on “swapon /dev/sda1”
    • format the partition “mkfs.ext4 -L nixos /dev/sda2”
    • mount the formatted partition “mount /dev/disk/by-label/nixos /mnt”
    • generate the default config file “nixos-generate-config –root /mnt”
    • edit the configuration file “nano /mnt/etc/nixos/configuration.nix”
      • boot.loader.grub.device = “/dev/sda”
      • services.openssh.enable = true
      • I must have janked the user creation because it did not work as expected
    • install NixOS “nixos-install”
    • shutdown the VM “halt”
    • power off the VM from the VirtualBox GUI
    • eject the virtual CDROM
    • add a second network adapter “host-only”
    • re-start the VM
At this point you are pretty close but if you are using VirtualBox you’ll have to do at least one more thing in order to be able to ssh into your newly minted system.  Create a new user:
  • login as the root user. Right now the root user does not have a password
  • change the root user’s password “passwd”
  • create the new user “useradd -m myusername”
  • change the user’s password “passwd myusername”
  • and if the user is an admin user then you need to add this user to the admin group “user mod -G wheel myusername”
Now you should be able to ssh into the VM from your host computer with your newly minted username. I installed vim in my user account because I like it as my preferred editor. 

At this point I shutdown and created a snapshot so that I could return to this state or create clones of my NixOS installation. I hope to find myself going through a number of use-cases shortly:
  • installing packages from the unstable channel
  • using containers
  • installing the Hydra CI
  • trying to determine the Docker play
  • determining the host upgrade workflow
  • physical drive crypto
  • golang and other compiler tech as part of the development stack
  • fossil and/or the hydra storage
It’s fun to note that my first 16GB installation left me with 12GB free after the base OS and vim were installed. Based on the way the packages are installed it appears that NixOS is going to take more diskspace than a like Ubuntu or Fedora, however, there may be other economies that are yet to be discovered.