1.2 KiB
Rolling Back Configuration Changes
After running nixos-rebuild to switch to a new configuration, you may
find that the new configuration doesn't work very well. In that case,
there are several ways to return to a previous configuration.
First, the GRUB boot manager allows you to boot into any previous configuration that hasn't been garbage-collected. These configurations can be found under the GRUB submenu "NixOS - All configurations". This is especially useful if the new configuration fails to boot. After the system has booted, you can make the selected configuration the default for subsequent boots:
# /run/current-system/bin/switch-to-configuration boot
Second, you can switch to the previous configuration in a running system:
# nixos-rebuild switch --rollback
This is equivalent to running:
# /nix/var/nix/profiles/system-N-link/bin/switch-to-configuration switch
where N is the number of the NixOS system configuration. To get a
list of the available configurations, do:
$ ls -l /nix/var/nix/profiles/system-*-link
...
lrwxrwxrwx 1 root root 78 Aug 12 13:54 /nix/var/nix/profiles/system-268-link -> /nix/store/202b...-nixos-13.07pre4932_5a676e4-4be1055