Emc Corporation

Emc Coropration

David W DesRoches

Kiran Prakash Madnani

Roy E Clark

Ruben Michel

Victoria Dubrovsky

Robert C Solomon

Tao Kai Lam

Steve Morley

Avinoam Zakai

Shai Bar-Nefy

John Percy

Randall Shain

Ron Arnan

Michael F Brown

Stephen J Todd

Andreas L Bauer

Eitan Bachmat

David Kurt Spencer

A method and computer program product for dividing a cache memory system into a plurality of cache memory portions. Data to be written to a specific address within an electromechanical storage system is received. The data is assigned to one of the plurality of cache memory portions, thus defining an assigned cache memory portion. Association information for the data is generated, wherein the association information defines the specific address within the electromechanical storage system. The data and the association information is written to the assigned cache memory portion.

Cache management system and method

A system, computer program product, and computer-implemented method for defining a data stripe that spans one or more of N data storage devices and one or more of M erasure code devices. The one or more N data storage devices and the one or more M erasure code devices are included within a data storage system. A data chunk to be written to the data storage system is received. At least a portion of the data chunk is written to the portion of the data stripe that spans the one or more N data storage devices. Each of the N data storage devices and the M erasure code devices is included within a unique server computer.

Data caching system and method

A method, computer program product, and storage network system for detecting a failure of a highly-available, volatile, solid state cache memory system included within a storage network. The highly-available, volatile, solid state cache memory system includes cache data. The cache data is replicated onto a non-volatile, solid-state, cache memory system included within the storage network. At least one data request concerning the highly-available, volatile, solid state cache memory system is redirected to the non-volatile, solid-state, cache memory system.

Auto-adapting multi-tier cache

A system, method and computer program product for detecting an additional storage device within an 'n' device array. The 'n' device array is configured to store &#x201c;n&#x201d; device array formatted data. The &#x201c;n&#x201d; device array is reconfigured into an &#x201c;n+m&#x201d; device array. The &#x201c;n&#x201d; device array formatted data is written to the &#x201c;n+m&#x201d; device array in an &#x201c;n+m&#x201d; device array format. Reconfiguring the &#x201c;n&#x201d; device array may include converting the &#x201c;n&#x201d; device array formatted data into &#x201c;n+m&#x201d; device array formatted data. The &#x201c;n+m&#x201d; device array may comprise two storage devices including a mirrored storage device, or may include at least three storage devices including a coded target storage device such as a parity storage device. The coded target storage device may be a distributed coded target as in a RAID array.

System and method for configuring a device array upon detecting addition of a storage device

A method and computer program product for receiving a newly-received data portion for storing within a cache memory system. A determination is made concerning whether the newly-received data portion corresponds with at least one data portion previously written to a non-volatile, memory system. If the newly-received data portion does not correspond with at least one previously-written data portion, the newly-received data portion is stored within the cache memory system using a protected data storage methodology.

System and method for improving cache efficiency

A method and computer program product for dividing a cache memory system into a plurality of cache memory portions. Data to be written to a specific address within an electromechanical storage system is received. The data is assigned to one of the plurality of cache memory portions, thus defining an assigned cache memory portion. Association information for the data is generated, wherein the association information defines the specific address within the electromechanical storage system. The data and the association information is written to the assigned cache memory portion. A method and computer program product for receiving a data read request concerning requested data stored at a specific address within an electromechanical storage system. A potential cache memory portion within a cache memory system may be identified, wherein the potential cache memory portion is chosen from a plurality of cache memory portions included within the cache memory system. The potential cache memory portion may be read to obtain portion content, wherein the portion content includes portion data stored within the potential cache memory portion and association information concerning the portion data. The association information may be processed to determine if the portion data is equivalent to the data stored at the specific address within the electromechanical storage system.

A method and computer program product for receiving a newly-received data portion for storing within a cache memory system. A determination is made concerning whether the newly-received data portion corresponds with at least one data portion previously written to and currently resident on the cache memory system. If the newly-received data portion does not correspond with at least one previously-written and currently resident data portion, the newly-received data portion is written to the cache memory system.

A system, method and computer program product for receiving on a non-volatile, solid-state, cache memory system, a data segment, including a plurality of data elements, from one or more of a volatile, solid-state, cache memory system and a non-volatile, electromechanical memory system. The data segment may be stored on the non-volatile, solid-state, cache memory system. Each data element includes one or more data extents.

System and method for flash-based data caching

A system, method and computer program product for detecting a failed storage device within an 'n' device array. The 'n' device array is configured to store &#x201c;n&#x201d; device array formatted data. The &#x201c;n&#x201d; device array is reconfigured into an &#x201c;n&#x2212;1&#x201d; device array. The &#x201c;n&#x201d; device array formatted data is written to the &#x201c;n&#x2212;1&#x201d; device array in an &#x201c;n&#x2212;1&#x201d; device array format.

Auto-adapting cache memory system and method

A clustered storage array consists of multiple nodes coupled to one or more storage systems. The nodes provide a LUN-device for access by a client. The LUN-device maps to a source logical unit corresponding to areas of storage on the one or more storage systems. A target logical unit corresponds to different areas of storage on the one or more storage systems. The source logical unit is migrated in parallel by the multiple nodes to the target logical unit. Data to be copied from the source logical unit to the target logical unit are grouped into data chunks. Two or more of the plurality of nodes concurrently attempt to acquire an exclusive lock for a set of data chunks. The node acquiring the exclusive lock migrates the set of data chunks from the source logical unit to the target logical unit, while the exclusive lock is used to prevent other nodes from migrating the set of data chunks.

Method to perform parallel data migration in a clustered storage environment

Auto-adapting cache memory system and memory

A technique protects shared data in a local device having local memory. The technique involves observing a page table entry (PTE) on the local device. The PTE is stored in a page table used for managing virtual to physical address translations, tracking page modifications and handling page faults between semiconductor memory and magnetic disk drive memory on the local device. The technique further involves leaving a mirroring routine inactive on the local device when the PTE indicates that shared data corresponding to the PTE has not been modified on the local device. The mirroring routine is configured to copy the shared data from the local memory to a remote device. The technique further involves activating the mirroring routine to mirror the shared data from the local memory to the remote device when the PTE indicates that shared data corresponding to the PTE has been modified on the local device.

Techniques for mirroring data within a shared virtual memory system

A technique involves providing access to shared data based on enhanced standard virtual memory mechanisms. Once data from a shared area of memory is moved into primary memory of a first computerized device from a second computerized device, the first computerized device can retain that data in order to shorten the latency of subsequent accesses. Such a technique can be configured to handle shared data at the sub-page-granular level using sparse virtual pages to minimize memory access contention and thus improve the likelihood of quick re-hits. Furthermore, such a technique can be conveniently accomplished through an enhancement to a common page fault handler of an operating system and utilizing atomic remote access support from a standard communications protocol thus alleviating the need to employ more costly and complicated solutions such as inflexible hardware implementations or independent programs that could pose additional design burdens and reliability concerns.

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Methuen, MA, United States of America

David W DesRoches