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nixos-build-vms - Man Page

build a network of virtual machines from a network of NixOS configurations


nixos-build-vms [--show-trace] [--no-out-link] [--help] [--option name value] network.nix


This command builds a network of QEMU-KVM virtual machines of a Nix expression specifying a network of NixOS machines. The virtual network can be started by executing the bin/run-vms shell script that is generated by this command. By default, a result symlink is produced that points to the generated virtual network.

A network Nix expression has the following structure:

  test1 = {pkgs, config, ...}:
      services.openssh.enable = true;
      nixpkgs.localSystem.system = "i686-linux";
      deployment.targetHost = "test1.example.net";

      # Other NixOS options

  test2 = {pkgs, config, ...}:
      services.openssh.enable = true;
      services.httpd.enable = true;
      environment.systemPackages = [ pkgs.lynx ];
      nixpkgs.localSystem.system = "x86_64-linux";
      deployment.targetHost = "test2.example.net";

      # Other NixOS options

Each attribute in the expression represents a machine in the network (e.g. test1 and test2) referring to a function defining a NixOS configuration. In each NixOS configuration, two attributes have a special meaning. The deployment.targetHost specifies the address (domain name or IP address) of the system which is used by ssh to perform remote deployment operations. The nixpkgs.localSystem.system attribute can be used to specify an architecture for the target machine, such as i686-linux which builds a 32-bit NixOS configuration. Omitting this property will build the configuration for the same architecture as the host system.


This command accepts the following options:


Shows a trace of the output.


Do not create a 'result' symlink.

-h,  --help

Shows the usage of this command to the user.

--option name value

Set the Nix configuration option name to value. This overrides settings in the Nix configuration file (see nix.conf(5)).


Eelco Dolstra



01/01/1980 NixOS Reference Pages