Abstract: A method, apparatus, and system for implementing a multi-level redundant array of independent disks (RAID) architecture to increase data storage system performance and/or redundancy of data. In one embodiment, the RAID architecture includes, at the lowest or n-th layer, a plurality of nodes or storage devices implementing striped, mirrored, and/or other RAID algorithm, and assigned a system identification or LUN (logical unit number). Each LUN is part of a larger data storage system that may employ one or more other RAID organizations such as a RAID 4 or RAID 5.

Abstract: A mass storage subsystem is connectable to a host computer via a host adapter and includes a subsystem bus extending from the host adapter to at least one base unit and a removable disk drive cartridge for use with the base unit. A control signal path extends between the base unit and the removable disk drive cartridge when it is installed and connected within the base unit. The disk drive cartridge includes a housing, at least one storage disk rotatably mounted within the housing, at least one data transducer head within the housing and positionable by a head positioner at selected concentric data storage tracks defined on a storage surface of the storage disk. A bus interface circuit is provided for directly connecting to the subsystem bus when the cartridge is installed and connected within the base unit, and a cartridge controller is provided for controlling operations of the bus interface circuit and the head positioner and for communicating with the base unit via the control signal path.