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 high density storage device packaging apparatus in which storage devices are oriented to have lateral faces parallel to each other and to edges of a module in which the storage devices are mounted. The storage devices are connected to a board contained in the module by a plug-in action. The board contains a controller to control the operation of the storage devices including the READ and WRITE operations. The RSM is capable of holding a large number of storage devices and capable of being inserted into a cabinet by a plug-in connection. The RSM includes a housing that covers and protects the storage devices and includes air channels to allow the storage devices to cool. The invention provides a solution for high density packaging of the storage devices and allows for easy access to the storage devices and allows for replacement of failed storage devices without disruption of the remainder of storage devices in the RSM or in the cabinet.

Abstract: A method for preparing data units for access in a data storage system is disclosed. The data storage system includes multiple storage devices having data units. All the storage devices of the data storage system are not powered on at the same time. The method includes preparing and storing the auxiliary data. The auxiliary data is prepared for a data unit on a storage device that will be powered off during an access request of the data unit. The auxiliary data is stored on the storage devices so that the auxiliary data is likely to be available on a powered-on storage device when the data unit is the subject of an access request.

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: Methods and systems for maintaining data reliability in a particular disk drive that is powered off in a storage system are disclosed. The methods include checking a power budget to determine that sufficient power is available, powering on the particular disk drive, and checking the particular disk drive to detect an error. Further, the method includes correcting the particular disk drive when the error is detected.

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: Spare disk drive management in a storage system. The storage system comprises disk drives and spare disk drives. Spare disk drives are initially kept in power-off state. The storage system detects the failure of a disk drive and selects a spare disk drive to replace the failed disk drive. The spare disk drive is selected on the basis of spare selection criteria. The selected spare disk drive is powered-on and replaces the failed disk drive. Data on the failed disk drive can be reconstructed on the spare disk drive by using RAID parity techniques.

Abstract: A system for dampening vibrations of a plurality of disk drives in such a way that the packaging density of disk drives is optimized. This is achieved by attaching a device for dampening vibrations to a population set of disk drives. The population set of disk drives comprises a plurality of disk drives. The device for dampening vibrations comprises at least one rail assembly. A plurality of isolators is attached to the rail assembly. The isolators are composed of materials that attenuate vibration. The isolators dampen the vibrations of the population set and isolate the population set from external vibrations and shock.

Abstract: Methods and apparatuses for maintaining a particular disk drive that is powered off in a storage system are disclosed. The method includes powering on the particular disk drive and executing a test on the particular disk drive. The method further includes powering off the particular disk drive on completing the test.

Abstract: An apparatus and method for space-efficient and high throughput command and data routing in data storage systems is disclosed. The apparatus comprises a host interface, a transmit circuit, a receive circuit, a plurality of storage device interfaces, and a sub-link circuit at each storage device interface. The sub-link circuit performs certain functions when the storage device is in ready phase. When the storage device enters active phase, the sub-link circuit ceases to perform one or more of the functions. These are then performed by the transmit circuit or the receive circuit.

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: Methods for preventing the failure of disk drives in storage systems are disclosed. A system and a computer program product for preventing the failure are also disclosed. Factors relating to the aging or early onset of errors in a disk drive are monitored. These factors are then compared to thresholds. In case the thresholds are exceeded, an indication for the replacement of the disk drive is given. Sudden rises in the factors are also used to indicate the impeding failure of disk drives.

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: An apparatus and a method for improving the fault tolerance of storage systems by replacing disk drives, which are about to fail, are disclosed. The set of disk drives in a storage system are monitored to identify failing disk drives. A processing unit identifies the failing disk drive and selects a spare disk drive to replace the failing disk drive. The selected spare disk drive is powered on, and data from the failing disk drive is copied to the selected spare disk drive. A memory unit stores attributes and sensor data for the disk drives in the storage system. The attributes and sensor data are used by the processing unit to identify a failing disk drive. Attributes for disk drives are obtained by using SMART, and sensor data is obtained from environmental sensors such as temperature and vibration sensors.

Abstract: An interconnecting unit and method for data communication between a plurality of computer hosts and a plurality of storage devices. The interconnecting unit couples the hosts to the storage devices and enables the data communication. The interconnection includes a plurality device control units. Each of the device control unit allows multiple commands to be distributed to multiple storage devices. The communication through the interconnecting unit is strong enough to tolerate failure across one connection path between the hosts and the storage devices.