International Business Machines Corporation

Edi Shmueli

Binny Sher Gill

Haim Helman

Tamar Domany

Steven Robert Hetzler

James Lee Hafner

Julian Satran

Daniel Felix Smith

Wendy Ann Belluomini

Assaf Nitzan

Yariv Aridor

Venu Nayar

Leah Shalev

Zorik Machulsky

Antonius Paulus Engbersen

Yehuda Naveh

Thomas Basil Smith, Iii

Adnan M Agbaria

Eyal Lotem

Oleg Goldshmidt

Yevgeny Kliteynik

Yaniv Altshuler

Eitan Frachtenberg

Yoav Gal

Robert E Stockmeyer, Legal Representative

Eyal Lotern

A computing device-implemented method for implementing dynamic hierarchical memory cache (HMC) awareness within a storage system is described. Specifically, when performing dynamic read operations within a storage system, a data module evaluates a data prefetch policy according to a strategy of determining if data exists in a hierarchical memory cache and thereafter amending the data prefetch policy, if warranted. The system then uses the data prefetch policy to perform a read operation from the storage device to minimize future data retrievals from the storage device. Further, in a distributed storage environment that include multiple storage nodes cooperating to satisfy data retrieval requests, dynamic hierarchical memory cache awareness can be implemented for every storage node without degrading the overall performance of the distributed storage environment.

Dynamic hierarchical memory cache awareness within a storage system

Described is a system and computer program product for implementing dynamic hierarchical memory cache (HMC) awareness within a storage system. Specifically, when performing dynamic read operations within a storage system, a data module evaluates a data prefetch policy according to a strategy of determining if data exists in a hierarchical memory cache and thereafter amending the data prefetch policy, if warranted. The system then uses the data prefetch policy to perform a read operation from the storage device to minimize future data retrievals from the storage device. Further, in a distributed storage environment that include multiple storage nodes cooperating to satisfy data retrieval requests, dynamic hierarchical memory cache awareness can be implemented for every storage node without degrading the overall performance of the distributed storage environment.

A method for migrating a virtual machine (VM) in a computing environment is provided. The method comprises receiving a request to migrate a VM executing on a source host to a destination host; defining a recovery point to which the VM is restored during recovery from a fault; and iteratively copying a memory of the source host associated with the VM to the destination host. During the copying, the original state of each page in the memory is preserved. At some point, the VM suspends executing on the source host, copies state information associated with the VM to the destination host, and resumes executing on the destination host. If a fault is detected on the source host, the VM is restored to the recovery point using preserved information.

Live migration of virtual machines in a computing environment

Embodiments of the invention relate to throttling accesses to a flash memory device. The flash memory device is part of a storage system that includes the flash memory device and a second memory device. The throttling is performed by logic that is external to the flash memory device and includes calculating a throttling factor responsive to an estimated remaining lifespan of the flash memory device. It is determined whether the throttling factor exceeds a threshold. Data is written to the flash memory device in response to determining that the throttling factor does not exceed the threshold. Data is written to the second memory device in response to determining that the throttling factor exceeds the threshold.

Optimized flash based cache memory

A method, including assigning, to each tier in a storage system comprising multiple tiers, a respective range of priority scores, and calculating a compression ratio for a file stored on one of the multiple tiers. Using the compression ratio, a priority score is calculated for the file, and the file is migrated to the tier whose assigned range of priority scores includes the calculated priority score.

Compression-aware data storage tiering

The present invention provides a fault tolerant system and method for parallel job execution. In the proposed solution the job state and the state transition control are decoupled. The job execution infrastructure maintains the state information for all the executing jobs, and the job control units, one per-job, control the state transitions of their jobs. Due to the stateless nature of the control units, the system and method allow jobs to continue uninterrupted execution even when the corresponding control units fail.

Fault tolerant system for execution of parallel jobs

A method for job selection and resource allocation of massively parallel processors, the method includes: providing to a constraint satisfaction problem solver multiple domains, variables, and constraints representative of a massively parallel processor, of queued job requests and of jobs being processed by the massively parallel processor, and generating, by the constraint satisfaction problem solver a result representative of multiple jobs to be executed, at least partially in parallel, by multiple resources of the massively parallel processor.

Method and computer program product for job selection and resource allocation of a massively parallel processor

Techniques for maintaining connectivity between a remote application stored on a remote device and an application being executed in a system environment, wherein the system environment is migrated from a first device to a second device, are provided. A first connection between the remote application stored on the remote device and the application being executed in the system environment stored on the first device is established via a first communication over a first negotiation channel. The first negotiation channel connects a first socket layer interface linked to the application being executed in the system environment to a second socket layer interface linked to the remote application. The first connection between the remote application and the application being executed in the system environment is disconnected for migration of the system environment from the first device to the second device. Disconnecting the first connection is coordinated via the first negotiation channel. A second connection between the remote application stored on the remote device and an application being executed in the migrated system environment stored on the second device is established via a second communication over a second negotiation channel. The second negotiation channel connects a third socket layer interface linked to the application being executed in the migrated system environment to the second socket layer interface linked to the remote application.

Virtualizing sockets to enable the migration of a system environment

A system and method for unifying access to a physical memory by operations using virtual addresses of the same virtual address space are provided. The operations may be generated by at least one central processing unit (CPU operations) and/or by at least one IO device (IO operations). The system may include a bus arranged to transfer data and virtual addresses of the same virtual address space from the central processing unit (CPU) and the IO device to a unified memory management unit (UMMU), a unified memory management unit (UMMU) arranged to translate the virtual addresses to physical addresses, and to protect the physical memory from illegal access attempts of the CPU operations and the IO operations. The system may further include a memory controller arranged to manage access to the physical memory. The access is done by using physical addresses.

Method and system for unifying memory access for CPU and IO operations

A method for wiring allocation and switch configuration in a multiprocessor computer, the method including employing depth-first tree traversal to determine a plurality of paths among a plurality of processing elements allocated to a job along a plurality of switches and wires in a plurality of D-lines, and selecting one of the paths in accordance with at least one selection criterion.

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Haifa, Israel

Edi Shmueli