Emc IP Holding Company LLC

Dell Products Inc.

Other

Bar Harel

Uri Shabi

Maor Rahamim

Bar David

Dror Zalstein

Nir Bar Joseph

Mark Abashkin

Alexei Kabishcer

A method, computer program product, and computing system for receiving a user data page for storing in a storage system. An unaligned hash representation of the received user data page may be generated. The generated unaligned hash representation may be identified within a hash table, thus defining an identified hash representation. A user data page associated with the identified hash representation may be identified, thus defining an identified user data page. A hash offset reference of the identified user data page may be compared with a hash offset reference of the received user data page. A deduplication operation may be performed on the received user data page based upon, at least in part, the comparison of the hash offset reference of the identified user data page with the hash offset reference of the received user data page.

System and method for performing unaligned deduplication

Techniques described herein elect how data is deduplicated in a storage system. A similarity hash signature for a data unit is calculated. A digest table is searched for a similarity hash signature within a predetermined distance of the similarity hash signature for the data unit. Based on the search, either a similarity hash signature or a strong hash signature of the data unit is added to the digest table.

Elective deduplication

Updates are applied to a multi-entry bucket of a persistent multi-bucket hash table indexed by a hash index having a bucket portion and a collision portion, each entry of each bucket storing a corresponding value. The bucket is initially stored in a buffer and both a hash lookup structure and value lookup structure are generated for the bucket, the hash lookup structure usable to identify an entry of the bucket based on collision portion, the value lookup structure usable to identify an entry of the bucket based on value. For each update, a value of the update is applied to the value lookup structure to identify a corresponding entry, and the entry in the buffer is modified as required by the update. Subsequently the bucket in the buffer is persisted back to the hash table using the hash lookup structure.

Space-efficient persistent hash table data structure

A method, computer program product, and computer system for identifying, by a computing device, content in a first bucket in a first cache. It may be determined that a first portion of the content in the first bucket is a duplicate, wherein a second portion of the content in the first bucket may be unique. The first portion of the content in the first bucket may be deduplicated from the first cache. The second portion of the content may be stored in a second bucket in a second cache.

System and method for efficient background deduplication during hardening

An aspect of implementing amortized execution of updates for a hash table includes aggregating, within a data structure, updates to be executed for the hash table. The aggregated updates are distributed across a plurality of chunks in the data structure. An aspect also includes sorting, within each of the chunks, the updates according to respective bucket index values associated with the updates, and iteratively executing the sorted updates across each of the chunks in the data structure.

Amortized execution of updates to a hardened hash table

A method, computer program product, and computing system for receiving, at a node of a multi-node storage system, one or more updates to a reference count associated with a metadata block. One or more reference count deltas associated with the metadata block may be stored in a cache memory system of the node. An existing copy of the metadata block in a cache memory system of each other node of the multi-node storage system may be retained.

System and method for reducing reference count update contention in metadata blocks

An aspect includes splitting a table of buckets into a fixed number of domains. Each of the domains includes a corresponding subset of the buckets. An aspect also includes providing a spare bucket for each of the subsets of the buckets and providing a metadata structure for each of the domains. The metadata structure includes a head pointer that points to a first bucket of a corresponding subset of the buckets and a spare_bucket pointer that points to the spare bucket of the subset of the buckets. An aspect further includes providing a split-spare bucket pointer that interleaves, during updates to data, among the subset of buckets in the domain. Data subject to the updates is stored in the spare bucket for a corresponding one of the domains. An aspect also includes updating the head pointer and the spare_bucket pointer for corresponding domains in response to updating the data.

Managing hash tables in a storage system

A method, computer program product, and computing system for storing data in one or more buckets of a plurality of buckets in a first level. The data of the one or more buckets may be de-staged to a plurality of buckets in a second level. The one or more buckets may be invalidated in the first level. A range of valid buckets in the first level may be defined based upon, at least in part, invalidating the one or more buckets in the first level.

System and method for invalidating multi-level hash table buckets

A method, computer program product, and computer system for storing data in a bucket of a plurality of buckets. A spare bucket may be reserved in the plurality of buckets. A copy of the data may be stored in the spare bucket. A pointer to the data in the bucket and a pointer to the copy of the data in the spare bucket may be updated based upon, at least in part, storing the data in the bucket and storing the copy of the data in the spare bucket.

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Tel Aviv, Israel

Bar Harel