A command line tool to conveniently mount, unmount, (un)lock and safely power off storage devices on Linux with as few keystrokes as possible.

Uses UDisks as its backend, but may support other backends in the future (as well as other *nix systems).

See below for installation instructions.

Usage

Mounting / activating

The default action is to mount the filesystem(s) on the most recently discovered device:

$ om
Activate device:

1) /dev/sda1                 My USB                  (12.5G)
2) /dev/mmcblk0              My memory card          (116.5G)

Device [1]: ⏎

/dev/sda1: mounted at `/run/media/user/My USB`.

Devices are listed from most to least recent.

om also supports encrypted devices:

$ om
Activate device:

1) /dev/mmcblk0              My memory card          (116.5G)

Device [1]: ⏎

Passphrase to unlock /dev/mmcblk0: <REDACTED>⏎

/dev/mmcblk0: unlocked.
/dev/dm-1: mounted at `/run/media/user/My memory card`.

Unmounting / deactivating

Use om -u to unmount, lock (if encrypted) and power off a device for safe removal (if applicable). If symlinked to um, running it is equivalent to om -u:

$ um            # ...same as `om -u`
Deactivate device:

1) /dev/sdc1                 My HDD                    (1.6T)
   • /run/media/user/My HDD

Device [1]: ⏎

/dev/dm-1: unmounted.
/dev/sdc1: locked.
/dev/sdc: powered off.

Listing system devices

By default, om hides devices considered "system". You can use the -a flag to include all devices in the list.

Installation

Using Cargo

Since om is written in Rust, it can be installed using Cargo[^1]:

$ cargo install om-rs

For convenience, you may symlink om as um (a handy shortcut for om -u):

$ (cd ~/.cargo/bin/ && ln -s om um)

Nix and NixOS

Using Flakes

On flake-enabled NixOS, add om to your system flake inputs:

  inputs.om = {
    url = "git+https://codeberg.org/undltd/om.git";
    inputs.nixpkgs.follows = "nixpkgs"; # to use your system's nixpkgs version
  };

...and add om.packages.${system}.default to environment.systemPackages (where ${system} is your current system architecture).

Alternatively, om can be added to your profile:

$ nix profile install git+https://codeberg.org/undltd/om.git

Without flakes

On a NixOS system without flakes enabled, om can be installed system-wide using simply fetchTarball (idea borrowed from agenix):

# /etc/nixos/configuration.nix
{ pkgs, ... }:

let om = builtins.fetchTarball "https://codeberg.org/undltd/om/archive/main.tar.gz";
in {
  environment.systemPackages = [
   ...
   (pkgs.callPackage "${om}/default.nix" {})
   ...
  ];
}

Roadmap

1. Figure out a an optimal approach to internationalizaition and translation of UI messages.
2. Handle common errors (like device busy) inside ui instead of simply returning them from main as is.
3. Investigate running on FreeBSD (currently compiles but panics because of minor UDisks implementation differences) / other BSD.
4. Explore "fuzzy" non-interactive use - a way to specify the desired device on the command line upfront by providing a part of device path or label.
5. A potential "auto" mode: activating / deactivating the most recent device without confirmation.
6. A possible "headless" mode (e.g., for invokation by desktop keybindings) with freedesktop.org notifications on success / failure.
7. Support handling LVM and other less common devices.

[^1]: Unfortunately, the package name om is already taken on crates.io by a discontinued / retracted package, hence om-rs. Nevertheless, it is preferred to call this package om when packaged elsewhere, since the -rs suffix is not really meaningful.