Abstract: A memory system constructed in accordance with the invention receives data blocks and associated host LBAs from a host processor. The memory subsystem initially associates a check value with each received data block, each check value dependent upon a host LBA that is associated with the respectively received data block. The memory subsystem stores each received data block and associated check value as an "extended" data block. Thereafter, the memory subsystem, in response to a host processor request to access data corresponding to the associated host LBA, recovers the stored extended data block and determines from the check value stored therewith, if the address of the corresponding data and that provided by the host processor correspond. If the addresses correspond, the data block is transmitted to the host processor. If not, an error message is generated.

Abstract: The methods concern fully utilizing storage capacity in a heterogenous hierarchic disk array having storage disks of differing capacities. The disks are segmented into multiple regions. One method links non-contiguous regions from individual storage disks to form RAID areas. The RAID areas are mapped into a virtual storage space that provides a view of the physical storage space as a single storage volume. Data is then stored in these RAID areas according to different redundancy criteria, such as RAID Level 1 and RAID Level 5. A second method fully utilizes of storage capacity by configuring the heterogeneous disk array to employ a minimum of two equal-sized storage disks that have larger capacity than other individual storage disks in the disk array. The contiguous regions across the multiple disks are then grouped together to form the RAID areas.

Abstract: A disk array data storage system has a plurality of storage disks and a disk array controller for coordinating transfer of user data to and from the storage disks. A memory manager is provided to manage memory allocation and data storage on the disk array. The memory manager maintains a sufficient quantity of hot spare storage space that can be made available for reconstructing the user data and restoring redundancy in the event one of the storage disks fails. Until a disk fails, however, the memory manager uses the hot spare space to store user and redundant data while guaranteeing that the storage space can be used for rebuilding following a storage disk failure. In this manner, all storage disks in the array are used to store user data, and additionally to maintain storage space that can be easily made available for purposes of hot spare in the event of disk failure.

Abstract: A method is described for enlarging the storage capacity of a hierarchical disk array data storage system which stores data according to different levels of redundancy, or RAID levels. The method includes first mapping the physical storage space into a first virtual storage space having a plurality of RAID areas that extend across multiple storage disks in the disk array and comprise multiple stripes of segments from each storage disk. The first virtual storage space is mapped into a second virtual storage space having multiple virtual blocks. To enlarge storage capacity, one or more storage disks are added to the hierarchic disk array. To assimilate the new storage capacity, data in a selected existing RAID area is moved to another area on the disk array of equal or greater storage capacity. The mapping of the second virtual storage space to the first is updated to reflect the data movement.

Abstract: Data loss is selectively tracked within a hierarchic data storage system having multiple storage disks that define a physical storage space. The physical storage space is mapped into a first virtual storage space which presents the physical storage space as multiple RAID areas that store data according to various RAID levels, such as RAID Level 1 (mirror redundancy) or RAID Level 5 (parity redundancy). Individual RAID areas extend across multiple storage disks and include a region of physical storage space on individual storage disks. The first virtual storage space is mapped into a second virtual storage space which presents the physical storage space as multiple virtual blocks. The RAID areas are monitored to detect data loss. Upon detecting data loss within a region of a RAID area, this first region is marked as invalid. Upon detecting data loss within a second region of the same RAID area, the data storage system will determine the extent of data loss.

Abstract: A disk array data storage system has plural sets of storage disks connected to multiple corresponding I/O buses. Individual storage disks can be independently and asynchronously attached to or detached from corresponding interfacing slots of the I/O buses. The system has physical device drivers which represent the storage disks with respect to their connections to the interfacing slots of the I/O buses and physical device managers which represent the data kept on the storage disks. Interface drivers are provided to manage I/O transfers through corresponding I/O buses. When a particular storage disk is attached to or detached from an interfacing slot of an I/O bus, the interface driver corresponding to the I/O bus freezes all I/O requests that come from the physical device drivers that represent the storage disks in the set connected to the I/O bus. A configuration manager determines which interfacing slot the particular storage disk has been attached to or detached from.

Abstract: A data memory system has a hierarchic disk array of multiple disks, a disk array controller for coordinating data transfer to and from the disks, and a RAID management system for mapping two different RAID areas onto the disks. The RAID management system stores data in one of the RAID areas according to mirror redundancy, and stores data in the other RAID area according to parity redundancy. The RAID management system then shifts or migrates data between the mirror and parity RAID areas on the disks in accordance with a predefined performance protocol, such as data access recency or access frequency. The data memory system also includes a memory map store embodied as a non-volatile RAM. The memory map store provides persistent storage of the virtual mapping information used by the RAID management system to map the first and second RAID areas onto the disks within the disk array.

Abstract: A hierarchic disk array data storage system has multiple storage disks that define a physical storage space and a RAID management system that maps the physical storage space into two virtual storage spaces. A RAID-level virtual storage space presents the physical storage space as mirror and parity RAID areas where the mirror RAID areas store data according to RAID Level 1 and the parity RAID areas store data according to RAID Level 5. An application-level virtual storage space presents the physical storage space as multiple virtual blocks. The RAID management system migrates data between the mirror and parity RAID areas to optimize performance and reliability. To facilitate migration, the RAID management system guarantees a minimum of unused storage space that can be used to empty a RAID area for the purpose of converting the RAID level or other storage attribute of the RAID area. The minimum unused storage space is preferably equivalent in size to at least one largest parity RAID area.

Abstract: A computer storage management system responds to a recognition of an insufficiency of disk storage space available by converting inefficiently used storage space to efficiently used space and free space. The management system controls allocation of storage space to storage space consumers pursuant to an allocation ordering scheme which ensures fairness of storage space consumption among competing consumers. Generation of free storage space and allocation of space are substantially concurrent events, creating a continuous flow of space generation and space consumption. Storage space is consistently kept and used in an efficient manner, and competing processes are allocated storage space fairly and effectively.

Abstract: A disk array has a plurality of disks, a disk array controller for coordinating data transfer to and from the disks, and a RAID management system for mapping two different RAID areas onto the disks. The RAID management system stores data in one of the RAID areas according to mirror redundancy, and stores data in the other RAID area according to parity redundancy. The RAID management system then shifts or migrates data between the mirror and parity RAID areas on the disks in accordance with a predefined performance protocol, such as data access recency or access frequency.

Abstract: In a computer system employing a common bus that is shared by an initiator and a plurality of targets, there is provided a method and apparatus that prevents data stored in a buffer, when one of the targets temporarily suspends a data transfer with the initiator, from being overwritten, while simultaneously minimizing the number of interrupts that must be employed to effect the data transfer. According to the disclosed invention, the initiator is interrupted by a second target only after the transfer of data from the initiator to a first target has been temporarily suspended, and only after the second target has reselected the bus. After the second target has reselected the bus, data read from the second target and transferred to the initiator is stored in a synchronous stack in the initiator to prevent any data remaining in the buffer from being overwritten.

Abstract: A sealed substrate processing path has plural selectably isolatable vacuum deposition chambers along the path. A transporter carries substrates along the path and an independently controllable sputter deposition is performed in each deposition chamber on substrates therein. Substrates are loaded from a load chamber to a first deposition chamber while a vacuum is maintained in the first and load chambers. Substrates are transferred from a last deposition chamber to an unload chamber while a vacuum is maintained in the last and load chambers. Substrates are placed in the load chamber while the load and first chambers are isolated and are removed from the unload chamber while the last and unload chambers are isolated. In one embodiment, substrates travel succesively from the load chamber to first through fourth deposition chambers and then to the unload chamber.