udisks-daemon

udisks-daemon

Note: The udisks-daemon is primarily invoked by the system's init system (e.g., systemd) as a background service and generally does not accept direct user-specified command-line options. Its main interaction point is its D-Bus API.

--help
    Displays a help message and exits.

--version
    Displays version information and exits.

The udisks-daemon is the core D-Bus service of the udisks framework, designed to manage storage devices and their various operations on Linux systems. It acts as an interface for user-space applications and desktop environments to interact with disks, partitions, and removable media without requiring direct root privileges for every action. The daemon handles the detection of new storage devices, mounting and unmounting of filesystems, formatting disks, creating and deleting partitions, and managing cryptographic volumes like LUKS. It integrates with PolicyKit for authorization, ensuring secure and controlled access to sensitive disk operations. Typically, udisks-daemon runs in the background, automatically started by the system's init system (e.g., systemd), and its primary mode of interaction is through its D-Bus API, rather than direct command-line arguments for users.

Requires PolicyKit for authorization; misconfiguration can lead to permission denied errors for disk operations.
Primarily designed for D-Bus interaction, not direct command-line use by end-users.
Not to be confused with udisksctl, which is the command-line client for interacting with the udisks-daemon.

The primary way to interact with udisks-daemon is through its D-Bus interface. This allows graphical file managers, desktop environments (like GNOME, KDE), and other applications to discover, inspect, and manipulate storage devices programmatically. Common D-Bus methods include mounting/unmounting, formatting, and ejecting devices.

For security, udisks-daemon relies heavily on PolicyKit (also known as polkit) to manage authorization for privileged operations. When an application requests an action that requires elevated permissions (e.g., formatting a drive), PolicyKit policies determine whether the calling user is authorized, often prompting for a password or requiring membership in specific groups.

The udisks project, which includes udisks-daemon, emerged as a replacement for HAL (Hardware Abstraction Layer) and DeviceKit-disks, aiming to provide a more modern and robust D-Bus interface for storage device management.
Initially, udisks1 was developed, with its daemon often named udisksd. It was later succeeded by udisks2, which introduced significant improvements and is the current standard. udisks-daemon refers specifically to the daemon component of the udisks2 framework.

udisksctl(1), mount(8), lsblk(8), fdisk(8), parted(8), systemd(1), polkit(8), udev(7)