By default, nixos-anywhere will reformat all configured disks before running the
installation. However it is also possible to mount the filesystems of an
existing installation and run nixos-install. This is useful to recover from a
misconfigured NixOS installation by first booting into a NixOS installer or
recovery system.
To only mount existing filesystems, add --disko-mode mount to
nixos-anywhere:
nix run github:nix-community/nixos-anywhere -- --disko-mode mount --flake <path to configuration>#<configuration name> --target-host root@<ip address>
- This will first boot into a nixos-installer
- Mounts disks with disko
- Runs nixos-install based on the provided flake
- Reboots the machine.