dadm

DADM, often written dadm, is a Linux user-space tool for managing software RAID arrays. It is positioned as an alternative to the mdadm utility, offering a declarative configuration approach and automation features intended to simplify maintenance of Linux software RAID arrays.

Overview and goals: The project aims to provide reproducible, version-controlled configuration for arrays, enabling creation, assembly, online/offline management, and repair based on a written configuration rather than ad hoc CLI commands. It operates alongside the kernel MD subsystem using standard /dev/md devices and status interfaces.

Usage and features: Users define arrays and their member devices in a configuration file. DADM can create new arrays, assemble existing ones, bring arrays online at boot, and manage resynchronization after failures. It may offer status reporting, event hooks, and integration with systemd or other init systems for automatic startup and monitoring.

Compatibility and scope: DADM is designed to work with Linux software RAID through the MD subsystem. While it shares goals with mdadm, its declarative workflow and automation model distinguish it from more traditional command-line tools. Documentation and community support are typically smaller than for mdadm.

See also: Linux MD device, mdadm, RAID, software RAID.