Sandisk Technologies Inc.

Gregory N Gillis

Nisha D Talagala

Swaminathan Sundararaman

Jingpei Yang

Ned Plasson

Robert Barry Wood

A storage module may be configured to perform log storage operations on a storage log maintained on a non-volatile storage medium. An I/O client may utilize storage services of the storage module to maintain an upper-level log. The storage module may be configured to coordinate log storage and/or management operations between the storage log and the upper-level log. The coordination may include adapting a segment size of the logs to reduce write amplification. The coordination may further include coordinating validity information between log layers, adapting log grooming operations to reduce storage recovery overhead, defragmenting upper-level log data within the storage address space, preventing fragmentation of upper-level log data, and so on. The storage module may coordinate log operations by use of log coordination messages communicated between log layers.

Systems and methods for log coordination

A cache and/or storage module may be configured to reduce write amplification in a cache storage. Cache layer write amplification (CLWA) may occur due to an over-permissive admission policy. The cache module may be configured to reduce CLWA by configuring admission policies to avoid unnecessary writes. Admission policies may be predicated on access and/or sequentiality metrics. Flash layer write amplification (FLWA) may arise due to the write-once properties of the storage medium. FLWA may be reduced by delegating cache eviction functionality to the underlying storage layer. The cache and storage layers may be configured to communicate coordination information, which may be leveraged to improve the performance of cache and/or storage operations.

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Riverton, UT, United States of America

Gregory N Gillis