Nixos-generate-config

Generate NixOS configuration modules.

This command is part of the nixos-install-tools package. It analyzes your hardware configuration and generates two files of:

• /etc/nixos/configuration.nix - the main system configuration file.
• /etc/nixos/hardware-configuration.nix - a hardware-specific configuration file, including detected devices and modules.

Usage

# nixos-generate-config

This will create configuration files based on the currently mounted system. This is typically used where NixOS is already installed. By default, nixos-generate-config will not overwrite an existing configuration.nix. To force overwrite an existing file, pass the --force option.

Generate configuration for a target root

To generate configuration files with a specific root directory (commonly used during installation):

# nixos-generate-config --root /mnt

This writes configuration files to /mnt/etc/nixos/.

Show hardware configuration

To print the detected hardware configuration to standard output without writing to disk:

# nixos-generate-config --show-hardware-config

Hardware specific notes

If you are using an SSD it may be useful to enable TRIM support as well as set filesystem flags to improve the SSD performance:

❄︎ /etc/nixos/configuration.nix

fileSystems."/".options = [ "noatime" "nodiratime" "discard" ];

A collection of hardware specific platforms with their config can be found at NixOS Hardware repository