Avago Technologies General IP (singapore) Pte. Ltd.

Lsi Corporation

Sujan Biswas

Sumanesh Samanta

Horia Cristian Simionescu

Mark Ish

Luca Bert

Karimulla Sheik

Debal Krishna Mridha

Naga S Vadalamani

A system and method for managing cache memory of at least one node of a multiple-node storage cluster. A first cache data and a first cache metadata are stored for data transfers between a respective node and regions of a storage cluster receiving at least a first selected number of data transfer requests. When the node is rebooted, a second (new) cache data is stored to replace the first (old) cache data. The second cache data is compiled utilizing the first cache metadata to identify previously cached regions of the storage cluster receiving at least a second selected number of data transfer requests after the node is rebooted. The second selected number of data transfer requests is less than the first selected number of data transfer requests to enable a rapid build of the second cache data.

System and method of rebuilding READ cache for a rebooted node of a multiple-node storage cluster

A method and system for IO processing in a storage system is disclosed. In accordance with the present disclosure, a controller may take long term 'lease' of a portion (e.g., an LBA range) of a virtual disk of a RAID system and then utilize local locks for IOs directed to the leased portion. The method and system in accordance with the present disclosure eliminates inter-controller communication for the majority of IOs and improves the overall performance for a High Availability Active-Active DAS RAID system.

Leased lock in active-active high availability DAS systems

The disclosure is directed to a system and method for managing READ cache memory of at least one node of a multiple-node storage cluster. According to various embodiments, a cache data and a cache metadata are stored for data transfers between a respective node (hereinafter 'first node') and regions of a storage cluster. When the first node is disabled, data transfers are tracked between one or more active nodes of the plurality of nodes and cached regions of the storage cluster. When the first node is rebooted, at least a portion of valid cache data is retained based upon the tracked data transfers. Accordingly, local cache memory does not need to be entirely rebuilt each time a respective node is rebooted.

System and method of selective READ cache retention for a rebooted node of a multiple-node storage cluster

System and techniques for rebuilding a redundant secondary storage cache including a first storage device and a second storage device are described. A metadata entry indicative of a validity of a portion of information stored by a first storage cache device and associated with a region of a primary storage device is received. When the validity of the portion of information associated with the region of the primary storage device is established, a region lock is requested on the region of the primary storage device associated with the portion of information stored by the first storage cache device. Then, the portion of information and the corresponding metadata entry associated with the region of the primary storage device is copied from the first cache storage device to a second storage cache device to rebuild the second storage cache device.

Rebuild of redundant secondary storage cache

A high availability DAS system uses a solid state cache to provide near active-active performance in a DAS duster, while retaining the implementation simplicity of active-passive or dual active system. Each node in the duster may include a solid state cache that stores hot I/O in an active-active mode, which allows the data to be read from or written to the underlying dual-active or active/passive DAS RAID system only when access to the 'hot Region' cools down or in the case of Cache Miss. The hot I/O data includes hot read data that accumulated dynamically regardless of ownership of the drives where the hot read data is permanently stored. The hot I/O data also includes hot write data that is mirrored across the solid state cache memories to avoid potential dirty write data conflicts and also to provide High Availability in case of server failures.

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Bengaluru, India

Sujan Biswas