Abstract: A test system for testing a multitasking computing device, such as a RAID storage device is described. The multitasking computing device is responsive to an inject fault command by entering a pre-determined mode of operation wherein the device maintains its present state and all command processing is terminated. As a result, the device becomes non-responsive to further commands. The test system includes a plurality of test programs. Each of the test programs being operable, when executed, to (a) test an associated function of the device and (b) transmit the inject fault command to the device if the test fails. In addition, each program is further operable, when executed, to (c) discontinue testing the device if the device becomes non-responsive. The test system further includes a processor and a multitasking operating system for executing the test programs concurrently.

Abstract: A RAID data storage system includes a heterogenous disk array coupled to a controller. The disk array provides a storage space that includes a first set of stipes each having at least “N” blocks and a second set of stripes each having less than “N” blocks. The controller can operate to map the storage space into redundant units by creating at least one redundant unit for storing data according to a mirror redundancy scheme. The redundant unit includes a block from the first set of stripes and a block from the second set of stripes.

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 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. The RAID-level virtual storage space presents the physical storage space as mirror and parity RAID areas where the mirror RAID areas contain mirror allocation blocks to store data according to RAID Level 1 and the parity RAID areas contain parity allocation blocks to store data according to RAID Level 5. The 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 ensure that sufficient space is retained for this migration, the RAID management system limits the number of virtual blocks that are allocated in the mirror RAID areas.

Abstract: A hierarchic disk array data storage system has a disk array with multiple storage disks and a disk array controller which coordinates data transfer to and from the disks. The storage disks define a physical storage space. A RAID management system maps a RAID-level virtual storage space onto the physical storage space. The RAID-level virtual storage space presents the physical storage space as multiple RAID areas. The RAID areas include mirror RAID areas which contain mirror allocation blocks to store data according to mirror redundancy and parity RAID areas which contain parity allocation blocks to store data according to parity redundancy. The RAID management system dynamically migrates data between the mirror and parity RAID areas in a manner which optimizes performance and data reliability. As new storage requests are made, the RAID management system evaluates the existing storage conditions and computes a total virtual capacity that is available to the user given a disk array configuration.

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.