International Business Machines Corporation

Infinidat Ltd.

Venu Nayar

Steven Robert Hetzler

Binny Sher Gill

James Lee Hafner

Daniel Felix Smith

Wendy Ann Belluomini

Haim Helman

Qun Fan

Assaf Nitzan

Edi Shmueli

Krishnakumar Rao Surugucchi

Eyal Lotem

Eyal Lotern

A method for service level agreement allocation of permanent storage layer resources of a storage system, the method may include monitoring, by a control layer of the storage system, actual performances of the storage system that are related to multiple logical volumes; calculating actual-to-required relationships between the actual performances and service level agreement defined performances of the multiple logical volumes; allocating, for different logical volumes of the multiple logical volumes, allowable amounts of pending access requests; wherein the allocating is based on, at least, the actual-to-required relationships; receiving, by the control layer, received access requests aimed to one or more logical volumes of the logical volumes; and sending to the permanent storage layer requests to serve at least some of the received access requests, based on the allowable amounts of pending access requests.

Service level agreement based management of pending access requests

A method for service level agreement (SLA) allocation of resources of a cache memory of a storage system, the method may include monitoring, by a control layer of the storage system, actual performances of the storage system that are related to multiple logical volumes; calculating actual-to-required relationships between the actual performances and SLA defined performances of the multiple logical volumes; assigning caching priorities, to different logical volumes of the multiple logical volumes; wherein the assigning is based on, at least, the actual-to-required relationships; and managing, based on at least the caching priorities, a pre-cache memory module that is upstream to the cache module and is configured to store write requests that (i) are associated with one or more logical volumes of the different logical volumes and (ii) are received by the pre-cache memory module at points in time when the cache memory is full; wherein the managing comprises transferring one or more write requests from the pre-cache memory module to the cache memory when the cache memory is not full.

Service level agreement based management of a pre-cache module

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

Embodiments of the invention enable a storage cache, comprising flash memory devices, to have direct block access to the flash such that the physical block addresses are presented to the storage system's cache layer, which thereby controls the storage cache data stream. An aspect of the invention includes a caching storage system. The caching storage system comprises a plurality of flash memory units organized in an array configuration. Each of the plurality of flash memory units includes at least one flash memory device and a flash unit controller. Each flash unit controller provides the caching storage system with direct physical block access to its corresponding at least one flash memory device. The caching storage system further comprises a storage cache controller. The storage cache controller selects physical block address locations (within a flash memory device) to be erased where data are to be written, issues erase commands to a flash unit controller corresponding to the selected physical block address locations, and issues page write operations to a set of erase blocks.

Storage system cache using flash memory with direct block access

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San Jose, CA, United States of America

Venu Nayar