nixos-rebuild

reconfigures a NixOS system by building a new configuration

TLDR

Build the configuration, activate it, and make it the boot default

$ sudo nixos-rebuild switch

Build from a flake rather than `/etc/nixos`

$ sudo nixos-rebuild switch --flake [path/to/flake]#[hostname]

Check that the configuration still builds, changing nothing

$ nixos-rebuild dry-build

Print what activation would change

$ sudo nixos-rebuild dry-activate

Activate for this session only, leaving the boot entry alone

$ sudo nixos-rebuild test --fast

Stage the configuration for the next boot without activating it now

$ sudo nixos-rebuild boot --install-bootloader

Update every channel and rebuild

$ sudo nixos-rebuild switch --upgrade-all

Go back to the previous generation

$ sudo nixos-rebuild switch --rollback

List the generations, as JSON

$ nixos-rebuild list-generations --json

Boot the configuration in a virtual machine to try it out

$ sudo nixos-rebuild build-vm-with-bootloader

Deploy the configuration to a remote machine

$ nixos-rebuild switch --target-host [user]@[host] --use-remote-sudo

Print a full trace when evaluation fails

$ sudo nixos-rebuild switch --show-trace

SYNOPSIS

nixos-rebuild [switch|boot|test|build|build-vm] [--upgrade] [--rollback] [-p name]

nixos-rebuild reconfigures a NixOS system by building a new configuration from /etc/nixos/configuration.nix and optionally activating it. NixOS uses a declarative configuration model where the entire system is described in Nix expressions.Each build creates a new generation that can be selected at boot time. This allows safe rollback to previous working configurations if problems occur.

PARAMETERS

--upgrade

Update nixpkgs channel before building

--rollback

Roll back to previous generation

-p, --profile-name _name_

Name for the boot entry

--flake _uri_

Build from flake reference

--no-build-nix

Don't rebuild Nix during switch

--fast

Skip rebuilding Nix and documentation

--show-trace

Show detailed error traces

COMMANDS

switch

Build, activate, and make boot default

boot

Build and make boot default without activating

test

Build and activate without making boot entry

build

Build configuration without activating

build-vm

Build and open configuration in virtual machine

dry-build

Show what would be built

dry-activate

Show what would change on activation

list-generations

List available system generations

CAVEATS

Requires root privileges for most operations. Configuration errors prevent build completion. Large changes may require significant download and build time. The switch command restarts services that changed.

HISTORY

nixos-rebuild is part of NixOS, the Linux distribution based on the Nix package manager. NixOS was created by Eelco Dolstra and first released in 2003. It pioneered declarative system configuration and atomic upgrades with rollback capability.