Abstract: A method, system and computer program product for a generic data storage interface for local and remote networked storage is provided. It comprises providing a data storage interface accessible by an operating system, transmitting data from an application running on the operating system to the data storage interface and selectively storing the data using the same data storage interface in either a local or a remote networked storage location. Firmware for the common data storage interface assigns a unique identifier that classifies an I/O request as a local or remote networked I/O request and adds the I/O request to a common stack for local and remote networked data storage elements. When an I/O request is removed from the stack, the unique identifier is used to identify the I/O request as a local or remote networked I/O request. Local I/O requests are executed via a local bus such as PCI, or SCSI.

Abstract: A method and system for copying operating system information to said at least two storage devices, selectively hiding at least one, but not all, of the storage devices from being accessed by the operating system, and selectively revealing one or more of said hidden storage devices as needed to permit access to the information stored therein.

Abstract: A method and system for copying operating system information to said at least two storage devices, selectively hiding at least one, but not all, of the storage devices from being accessed by the operating system, and selectively revealing one or more of said hidden storage devices as needed to permit access to the information stored therein.

Abstract: A method and system for copying operating system information to said at least two storage devices, selectively hiding at least one, but not all, of the storage devices from being accessed by the operating system, and selectively revealing one or more of said hidden storage devices as needed to permit access to the information stored therein.

Abstract: A finite state machine (FSM) for a redundant array of independent disk includes a single process context that maintains an entire finite state required for input/output operations performed in a RAID system. The finite state is only updated in response to calls and call-backs. The call-backs can include procedure returns and interrupt signals. The call is received directly from an application program, and the call-backs are received from a driver and passed back directly to the application software by the finite state machine.

Abstract: A method and system enables data redundancy across servers, networks, and controllers by using standard redundant files as underlying storage for RAID subsystem configurations. A redundant array of independent disk (RAID) subsystem includes a front-end interface configured to process non-redundant requests received from a primary file system communicating with an application program. A back-end interface of the RAID subsystem is configured to process redundant requests corresponding to the non-redundant requests. The redundant requests to be issued to a secondary file system communicates with a block mode device including multiple physical storage devices.

Abstract: A method and system that allows the distribution of hot spare space across multiple disk drives that also store the data and redundant data in a fully active array of redundant independent disks, so that an automatic rebuilding of the array to an array of the identical level of redundancy can be achieved with fewer disk drives. The method configures the array with D disk drives of B physical blocks each. N user data and redundant data blocks are allocated to each disk drive, and F free blocks are allocated as hot spare space to each disk drive, where N+F<=B, and ((D?M)×F)>=N. Thus, rebuilding of data and redundant blocks of a failed disk drive in the free blocks of the remaining disk drives is enabled after M disk drive failures.

Abstract: A configurable RAID subsystem includes a user data array connected to a user application via a block I/O path, and a configuration array connected to a configuration application via the same block I/O path. The user data array processes user data access commands executed by the user application; and the configuration application processes configuration commands, the user data access commands and the configuration commands communicated to the user data array and the configuration array respectively, via the block I/O path. A dynamic identification is assigned to the user data array by the configuration array, and a static identification is assigned to the configuration array.

Abstract: A method and system enables data redundancy across servers, networks, and controllers by using standard redundant files as underlying storage for RAID subsystem configurations. A redundant array of independent disk (RAID) subsystem includes a front-end interface configured to process non-redundant requests received from a primary file system communicating with an application program. A back-end interface of the RAID subsystem is configured to process redundant requests corresponding to the non-redundant requests. The redundant requests to be issued to a secondary file system communicates with a block mode device including multiple physical storage devices.

Abstract: A configurable RAID subsystem includes a user data array connected to a user application via a block I/O path, and a configuration array connected to a configuration application via the same block I/O path. The user data array processes user data access commands executed by the user application; and the configuration application processes configuration commands, the user data access commands and the configuration commands communicated to the user data array and the configuration array respectively, via the block I/O path. A dynamic identification is assigned to the user data array by the configuration array, and a static identification is assigned to the configuration array.

Abstract: A method and system enables data redundancy across servers, networks, and controllers by using standard redundant files as underlying storage for RAID subsystem configurations. A redundant array of independent disk (RAID) subsystem includes a front-end interface configured to process non-redundant requests received from a primary file system communicating with an application program. A back-end interface of the RAID subsystem is configured to process redundant requests corresponding to the non-redundant requests. The redundant requests to be issued to a secondary file system communicates with a block mode device including multiple physical storage devices.

Abstract: A method and system that allows the distribution of hot spare space across multiple disk drives that also store the data and redundant data in a fully active array of redundant independent disks, so that an automatic rebuilding of the array to an array of the identical level of redundancy can be achieved with fewer disk drives. The method configures the array with D disk drives of B physical blocks each. N user data and redundant data blocks are allocated to each disk drive, and F free blocks are allocated as hot spare space to each disk drive, where N+F<=B, and ((D−M)×F)>=N. Thus, rebuilding of data and redundant blocks of a failed disk drive in the free blocks of the remaining disk drives is enabled after M disk drive failures.

Abstract: A system and method for updating parity based upon locking and unlocking of a storage stripe in a redundant array of independent disk (RAID) implementation is provided. The stripe includes a parity block. The stripe is locked to prevent colliding I/O operations from being performed thereto while a current I/O operation is underway with respect to the stripe. A parity buffer is maintained that is updated to include the current parity information for the stripe. The buffer is “swapped” with the parity buffer associated with a next waiting I/O operation request before the stripe is unlocked. The buffer continues to be swapped with further requests so long as another I/O operation request waits on the lock. When no further I/O operation request for the given stripe is detected, then the current parity buffer is written into the stripe parity block. The intervening swaps reduce the number of parity cache reads and writes, increasing efficiency.

Abstract: A system and method for changing between various levels and configurations of redundant array of independent disk (RAID) implementations is provided. A specialized driver establishes a specialized “morph” container in a top level above primary and secondary level containers. The morph container communicates with the host computer I/O and arranges mapping of data between an original source container configuration and a new destination configuration. A morph container mapping structure is implemented to accomplish the mapping therebetween. Where data is migrated from an original container space back into an original space, a temporary container can be established to facilitate the transfer between the space.

Abstract: A finite state machine (FSM) for a redundant array of independent disk includes a single process context that maintains an entire finite state required for input/output operations performed in a RAID system. The finite state is only updated in response to calls and call-backs. The call-backs can include procedure returns and interrupt signals. The call is received directly from an application program, and the call-backs are received from a driver and passed back directly to the application software by the finite state machine.

Abstract: An excIusive OR (XOR) accumulator engine efficiently generates parity from a group of data blocks temporarily stored in a memory of a data processing system. The XOR engine comprises an XOR logic circuit coupled to a multi-stage shift register for accumulating parity calculations generated by the logic circuit. Accumulation of parity within the shift register continues until all of the data blocks within the group have been processed by the logic circuit; thereafter, the data blocks and their generated parity are stored on multiple disks of the data processing system.

Abstract: A data storage system includes a multi-tasking processor which manages a write cache to identify adjacent blocks held in the write cache which are to be included in a next write operation, while at the same time handling data transfer requests from a system host. The processor monitors the write cache and when the cache has fewer than a predetermined number of storage locations free, initiates a block-merge task. The processor then determines which block in the write cache is least recently used and, based on virtual block numbers assigned to the data blocks, identifies the blocks in the write cache which are adjacent to the least recently used block and are within the same chunk as that block. The processor maintains a list of these adjacent blocks and the locations in which the blocks are held in the write cache.

Abstract: A method for reducing the number of I/O requests required to write data to a disk drive of a computer system. The computer system includes a read cache for storing old data read from the disk drive, and a write cache for storing new data to be written to the disk drive. The method selectively merges old data in the read cache with new data in the write cache to form at most two physically contiguous data segments which can be written to the disk drive with at most two I/O requests.

Abstract: A flexible and implementation efficient logic circuit for a FIFO based parity generator, for generating parity blocks for use in a computer system. The logic circuit being capable of generating a data block resulting from an XOR of logic "0" with every bit in the first of a series of data blocks and storing the resulting data block in a FIFO data structure. The contents of the stored block of data may then be XORed with the contents of subsequent blocks of data with the result being stored in the FIFO data structure. The stored data, which represents the parity block generated from the series of data blocks supplied to the FIFO based parity generator, may be read out of the FIFO based parity generator over a series of clock cycles. The logic circuit of the present invention may also be used as a temporary storage media or as a logical zero generator.

Abstract: A system for reducing the number of I/O requests required to write data to an redundant array of inexpensive disks (RAID) of a computer system including a host central processor unit and a memory buffer cache. The system includes determinations for writing new data stored in the cache to the disk drives, as stripes, using the least number of I/O requests possible. The system uses the best of two alternative techniques in which the parity for the stripe can be generated. A first procedure determines the number of I/O requests that would be required to generate the parity data from the entire stripe including the new data to be written to the disk drives. A second procedure determines the number of I/O requests that would be required to generate the parity data from the new data to be written to the disk drives and the old parity data of the stripe.