Abstract: A system and method for coupling a host to a drive in a high-capacity data storage system are disclosed. The data storage system comprises a number of drives arranged in a hierarchical manner. A control system is provided for controlling input/output of data and managing control signals. The control system comprises a hierarchy of controllers and switches. The control system receives a request for a drive from a host and couples the host to the requested drive through the hierarchy of controllers.

Abstract: A method of accessing a plurality of storage devices is disclosed. A system and a computer program product for emulating tape libraries are also disclosed. First and second virtual storage devices with first and second address spaces, respectively, are defined. The first and second address spaces are mapped to portions on each of a plurality of storage devices. The storage devices can be part of a power managed RAID system where all the storage devices are not powered on at one time. A stream of contiguous address values are received and a storage device is selected. Finally, data is stored on the portion of the selected storage device so that multiple data streams can be written at all times, even though all the storage devices are not powered on. Similarly, stored data may be retrieved from the selected storage device by traversing the scattered streams.

Abstract: A method for adaptation of data organization by a data storage system controller is disclosed. Data organization in a data storage system is adapted according to varying workload profiles and system constraints. The data storage system also consists of a plurality of data storage units. On receipt of a request to write data, various workload and data storage system parameters are determined. On the basis of these parameters, target data storage units and appropriate data organization schemes are optimally selected. In the case where the volume of data to be written is less than a threshold value, a RAID organization scheme is preferred. In this scheme the data is written to the selected drives simultaneously. In the case where the volume of data to be written is more than the threshold value, a power managed RAID organization scheme, where all data drives need not be simultaneously powered on, is used.

Abstract: A hybrid centralized and distributed processing system includes a switching device that connects a storage processor to one or more servers through a host channel processor. The switching device also connects the storage processor to one or more storage devices such as disk drive arrays, and to a metadata cache and a block data cache memory. The storage processor processes access request from one or more servers in the form of a logical volume or logical block address and accesses the metadata cache to determine the physical data address. The storage processor monitors the performance of the storage system and performs automatic tuning by reallocating the logical volume, load balancing, hot spot removal, and dynamic expansion of storage volume. The storage processor also provides fault-tolerant access and provides parallel high performance data paths for fail over.

Abstract: A method for adaptation of data organization by a data storage system controller is disclosed. Data organization in a data storage system is adapted according to varying workload profiles and system constraints. The data storage system also consists of a plurality of data storage units. On receipt of a request to write data, various workload and data storage system parameters are determined. On the basis of these parameters, target data storage units and appropriate data organization schemes are optimally selected. In the case where the volume of data to be written is less than a threshold value, a RAID organization scheme is preferred. In this scheme the data is written to the selected drives simultaneously. In the case where the volume of data to be written is more than the threshold value, a power managed RAID organization scheme, where all data drives need not be simultaneously powered on, is used.

Abstract: Systems and methods for providing scalable, reliable, power-efficient, high-capacity data storage, wherein large numbers of closely packed data drives having corresponding metadata and parity volumes are individually powered on and off, depending upon their respective usage. In one embodiment, the invention is implemented in a RAID-type data storage system which employs a large number of hard disk drives that are individually controlled, so that only the disk drives that are in use are powered on. The reduced power consumption allows the disk drives to be contained in a smaller enclosure than would conventionally be possible. In a preferred embodiment, the data protection scheme is designed to utilize large, contiguous blocks of space on the data disk drives, and to use the space on one data disk drive at a time, so that the data disk drives which are not in use can be powered down.

Abstract: Systems and methods for providing scalable, reliable, power-efficient, high-capacity data storage, wherein large numbers of closely packed data drives having corresponding metadata and parity volumes are individually powered on and off, depending upon their respective usage. In one embodiment, the invention is implemented in a RAID-type data storage system which employs a large number of hard disk drives that are individually controlled, so that only the disk drives that are in use are powered on. The reduced power consumption allows the disk drives to be contained in a smaller enclosure than would conventionally be possible. In a preferred embodiment, the data protection scheme is designed to utilize large, contiguous blocks of space on the data disk drives, and to use the space on one data disk drive at a time, so that the data disk drives which are not in use can be powered down.