Emc IP Holding Company LLC

Emc Corporation

Peter Yale Kushner

Jonathan I Krasner

Chakib Ouarraoui

Philip E Tamer

Daryl Francis Kinney

Brian K Bailey

James H Torrey

Kenneth Vineleaf

Patrick J McAdam

John D Sullivan

The system and methods disclosed herein relate to an improvement in automated data tiering technology. The systems and methods disclosed herein enhance database storage performance characteristics in myriad ways. First, the speed with which data can be relocated from one tier to another in a tiered data storage system is increased by reducing the number of sort cycles required to perform data relocation. In addition, data relocation among the tiers is performed on the backend by an offload engine, which results in uninterrupted access to read/write commands within the data storage system from a user's perspective on the frontend. Third, users are able to adjust the percentages of hot or cold data that are relocated within the database without having to alter the service level agreements. In this way, users can make spontaneous changes to performance characteristics related to the promotion and demotion of data stored within a tiered data storage system.

Positional indexing for a tiered data storage system

The system and methods disclosed herein relate to an improvement in automated data tiering technology. In these embodiments, users are able to weigh the importance of read, write, and pre-fetch operations in terms of tier placement within the data storage system. Data relocation evaluations are performed by an off-load engine, e.g., a graphics processing unit, which utilizes parallel processing on data arrays/vectors/extents. The data relocation candidates are identified via calculating a mobility score on an extent-by-extent basis. Data are then relocated within the various tiers of the data storage system.

Tiered data storage system using mobility scoring

Described are techniques for simulation of a data storage system configuration. The simulation state reflects the data storage system configuration in accordance with an application programming interface (API) model. API calls result in reading existing data storage system configuration data and/or modifying the configuration data by execution of one or more low level calls. A daemon may operate in a simulation mode in which the low level calls are simulated rather than resulting in communications with a data storage system when operating in a non-simulation mode. A low level cache is used to store simulated values returned from the data storage system microcode. A high level cache is used to store API call return data. A seed file is used to initialize the simulation state.

Application programming interface simulator for a data storage system

A method for detecting faulty equipment on a loop of disk drives in which error counts are obtained for each disk drive including an amount of invalid transmission words and/or a count of loop initialization protocols (LIPs) that have been initiated and received. Counts are obtained twice so as to detect changes to the error counts. Based on the error counts and LIP counts suspect disk drives may be recorded along with their electrical predecessor on the loop to permit expedited identification of faulty equipment.

Failure detection and isolation

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Fiskdale, MA, United States of America

Peter Yale Kushner