Abstract: A power saving archive system includes a front storage system accessible by clients and one or more back storage systems connected to the front storage system. A client file received by the front storage system is written to one of the back storage systems, while the front storage system stores a reference to the file and deletes the file from the front storage system after a certain time period. Each back storage system enters an inactive state (e.g. a powered off state) after a period of unuse, and can become active again in response to a wakeup command (e.g. a Wake-on-LAN signal) from the front storage system. Upon receiving a file read request from a client, the front storage system wakes up the appropriate back storage system, restores the file from the back storage system, and provides the file to the client.

Abstract: A power saving archive system includes a front storage system accessible by clients and one or more back storage systems connected to the front storage system. A client file received by the front storage system is written to one of the back storage systems, while the front storage system stores a reference to the file and deletes the file from the front storage system after a certain time period. Each back storage system enters an inactive state (e.g. a powered off state) after a period of unuse, and can become active again in response to a wakeup command (e.g. a Wake-on-LAN signal) from the front storage system. Upon receiving a file read request from a client, the front storage system wakes up the appropriate back storage system, restores the file from the back storage system, and provides the file to the client.

Abstract: A computing device having a unique form factor and adapted for connecting to an external device is described. The computing device includes external connector(s), computing node(s), a power unit, and a flexible enclosure structure encasing them. The enclosure structure is made of flexible materials so that the computing device forms a physically integrated unit free of a rigid frame and can be mechanically supported by its external connectors without a chassis. At least one computing node has a computing state machine and programs that controls the behavior of the computing nodes at least during a connection event and a disconnection event. The computing device can be hot-swapped and function properly between these events. Also described is a reconfigurable computing system that includes one or more computing devices described above and one or more host computers, as well as programming techniques for accomplishing hot swapping of the computing devices.

Abstract: A computing device having a unique form factor and adapted for connecting to an external device is described. The computing device includes external connector(s), computing node(s), a power unit, and a flexible enclosure structure encasing them. The enclosure structure is made of flexible materials so that the computing device forms a physically integrated unit free of a rigid frame and can be mechanically supported by its external connectors without a chassis. At least one computing node has a computing state machine and programs that controls the behavior of the computing nodes at least during a connection event and a disconnection event. The computing device can be hot-swapped and function properly between these events. Also described is a reconfigurable computing system that includes one or more computing devices described above and one or more host computers, as well as programming techniques for accomplishing hot swapping of the computing devices.

Abstract: A computing device having a unique form factor and adapted for connecting to an external device is described. The computing device includes external connector(s), computing node(s), a power unit, and a flexible enclosure structure encasing them. The enclosure structure is made of flexible materials so that the computing device forms a physically integrated unit free of a rigid frame and can be mechanically supported by its external connectors without a chassis. At least one computing node has a computing state machine and programs that controls the behavior of the computing nodes at least during a connection event and a disconnection event. The computing device can be hot-swapped and function properly between these events. Also described is a reconfigurable computing system that includes one or more computing devices described above and one or more host computers, as well as programming techniques for accomplishing hot swapping of the computing devices.

Abstract: An operating-system-independent modular programming method is disclosed, which includes providing one or more tasks, one or more task queues, and zero or more condition queues. Each task is a program that is run in sequence. Each task queue includes a task queue program and a queue containing zero or more tasks. Each condition queue includes a condition queue program and a queue containing zero or more tasks and associated conditions. Each task includes task ending code that refers to zero, one, or more than one successor task, and the task queue program or the condition queue program handles each such successor task by either running it or placing it in a task queue or a condition queue. The programming method further includes providing a fan and an end fan construct to enable a parent task to generate a plurality of child sequences.

Abstract: A general RAID conversion method is described for converting between different RAID configurations. The method includes reading a unit of user data from the source devices according to the source RAID algorithm, writing the user data together with redundant data (if any) to the target devices according to the target RAID algorithm, and from time to time releasing portions of the source devices containing data that has been converted. The conversion may be used to expand or contract the array, to increase or decrease usable capacity, and to increase or decrease the device-loss insurance level. Conversion may be performed on line (dynamically) or off line. The flexibility of the method allows the implementation of manual and/or rule-based RAID reconfiguration that automatically adjusts system parameters based on user request and/or a set of rules and conditions respectively. It may also be used to perform self-healing after one or more devices in the array have failed.

Abstract: An improved and extended Reed-Solomon-like method for providing a redundancy of m?3 is disclosed. A general expression of the codes is described, as well as a systematic criterion for proving correctness and finding decoding algorithms for values of m?3. Examples of codes are given for m=3, 4, 5, based on primitive elements of a finite field of dimension N where N is 8, 16 or 32. A Horner's method and accumulator apparatus are described for XOR-efficient evaluation of polynomials with variable vector coefficients and constant sparse square matrix abscissa. A power balancing technique is described to further improve the XOR efficiency of the algorithms. XOR-efficient decoding methods are also described. A tower coordinate technique to efficiently carry out finite field multiplication or inversion for large dimension N forms a basis for one decoding method.

Abstract: An improved and extended Reed-Solomon-like method for providing a redundancy of m?3 is disclosed. A general expression of the codes is described, as well as a systematic criterion for proving correctness and finding decoding algorithms for values of m>3. Examples of codes are given for m=3, 4, 5, based on primitive elements of a finite field of dimension N where N is 8, 16 or 32. A Horner's method and accumulator apparatus are described for XOR-efficient evaluation of polynomials with variable vector coefficients and constant sparse square matrix abscissa. A power balancing technique is described to further improve the XOR efficiency of the algorithms. XOR-efficient decoding methods are also described. A tower coordinate technique to efficiently carry out finite field multiplication or inversion for large dimension N forms a basis for one decoding method.

Abstract: Method and apparatus for providing data recovery in a one or multiple disk loss situation in a RAID5 like system. A data storage apparatus has a plurality of n disks storing data comprising a plurality of n data groupings stored across the plurality of n disks. Each one of the n data groupings comprises a data portion and a redundancy portion. The size of the data portion relative to the redundancy portion is as H to Q, where H/Q<(n?m)/m, where m is the maximum number of disks that may be lost at any given time. Advantageously, the n data portions are recoverable from any and all combinations of n-m data grouping(s) on n?m disk(s) when the other m data grouping(s) are unavailable, where 1?m<n.

Abstract: An operating-system-independent modular programming method is disclosed, which includes providing one or more tasks, one or more task queues, and zero or more condition queues. Each task is a program that is run in sequence. Each task queue includes a task queue program and a queue containing zero or more tasks. Each condition queue includes a condition queue program and a queue containing zero or more tasks and associated conditions. Each task includes task ending code that refers to zero, one, or more than one successor task, and the task queue program or the condition queue program handles each such successor task by either running it or placing it in a task queue or a condition queue. The programming method further includes providing a fan and an end fan construct to enable a parent task to generate a plurality of child sequences.

Abstract: Method and apparatus for providing data recovery in a one or multiple disk loss situation in a RAID5 like system. A data storage apparatus has a plurality of n disks storing data comprising a plurality of n data groupings stored across the plurality of n disks. Each one of the n data groupings comprises a data portion and a redundancy portion. The size of the data portion relative to the redundancy portion is as H to Q, where H/Q<(n−m)/m, where m is the maximum number of disks that may be lost at any given time. Advantageously, the n data portions are recoverable from any and all combinations of n-m data grouping(s) on n−m disk(s) when the other m data grouping(s) are unavailable, where 1≦m<n.