Sandisk Technologies Inc.

Longitude Enterprise Flash S.a.r.l.

Evan Orme

James G Peterson

Kevin Vigor

David Flynn

Michael Zappe

A storage layer is configured to store data at respective offsets within storage units of a storage device. Physical addresses of the data may be segmented into a first portion identifying the storage unit in which the data is stored, and a second portion that indicates the offset of the data within the identified storage unit. An index of the data offsets (e.g., second portions of the physical addresses) may be persisted on the storage device. The first portion of the address may be associated with logical addresses of the data in a forward index. The forward index may omit the second portion of the physical addresses, which may reduce the memory overhead of the index and/or allow the forward index to reference larger storage devices. Data of a particular logical address may be accessed using the first portion of the physical address maintained in the forward index, and the second portion of the media address stored on the storage device.

Systems and methods for referencing data on a storage medium

A storage controller identifies a storage division comprising unreadable data. In response, the storage controller relocates readable data (if any) from the identified storage division. The storage controller may be further configured to associate the unreadable data with a logical address, and to record persistent metadata to indicate that the logical address is mapped to unreadable, corrupt data. The storage controller may clear the corruption indicator from the logical address. The logical address may be cleared in response to determining that the unreadable data is invalid and/or available from another source.

Storage error management

A storage controller identifies a storage location within a storage division that corresponds to a high error rate. In response, the storage controller may refresh data stored on the storage division by relocating data from the storage division and/or initializing (e.g., erasing) the storage division. In some embodiments, the storage division is selectively refreshed by relocating data from the storage location(s) having high error rates, while deferring a full relocation of other data from the storage division. The storage division may be selectively refreshed based on reliability characteristics of the storage division, such as the remaining data retention time calculated for the storage division.

Adaptive storage reliability management

Apparatuses, systems, and methods are disclosed for indexing data of an append-only, log-based structure. A storage controller writes a plurality of data packets to a storage medium by sequentially appending the data packets to a log-based structure of the storage medium. The data packets may be associated with different logical identifiers belonging to a logical address space that is independent of physical storage locations on the storage medium. An indexing module writes an index segment associated with the plurality of data packets to the log-based structure. The index segment may include index entries for determining the logical identifiers of the data packets. The indexing module records, on the storage medium, information indicating where the index segment is written on the storage medium.

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Lindon, UT, United States of America

Evan Orme