Seagate Technology Incorporated

Quantum Corporation

James David Sawin

Sumanth Jannyavula Venkata

Mark A Gaertner

Ryan James Goss

Luke William Friendshuh

Bruce Douglas Buch

Russell W Brown

Nick Horgan

Yunaldi Yulizar

John A Scaramuzzo

Data storage devices may store selected data received from a data source to a buffer memory. The selected data may be copied from the buffer to a non-volatile memory configured for sequential storage. The selected data may then be copied from the buffer to a solid state memory, such as dynamic random access memory. The selected data may be copied from the solid state memory to a main store, such as a magnetic disc memory. If the selected data cannot be found in the solid state memory, the selected data in the non-volatile memory can be copied to the main store.

Cache management in data storage systems

A new segment of data is copied to a volatile, primary cache based on a host data read access request. The primary cache mirrors a first portion of a non-volatile main storage criterion is determined for movement of data from the primary cache to a non-volatile, secondary cache that mirrors a second portion of the main storage. The criterion gives higher priority to segments having addresses not yet selected for reading by the host. In response to the new segment of data being copied to the primary cache, a selected segment of data is copied from the primary cache to the secondary cache in response to the selected segment satisfying the criterion.

Determining a criterion for movement of data from a primary cache to a secondary cache

Host read operations affecting a first logical block address of a data storage device are tracked. The data storage device includes a main storage and a non-volatile cache that mirrors a portion of data of the main storage. One or more criteria associated with the host read operations are determined. The criteria are indicative of future read requests of second logical block address associated with the first logical block address. Data of the at least the second logical block address is copied from the main storage to the non-volatile cache if the criteria meets a threshold.

Criteria for selection of data for a secondary cache

Approaches for implementing a controller for a hybrid memory that includes a main memory and a cache for the main memory are discussed. The controller comprises a hierarchy of abstraction layers, wherein each abstraction layer is configured to provide at least one component of a cache management structure. Each pair of abstraction layers utilizes processors communicating through an application programming interface (API). The controller is configured to receive incoming memory access requests from a host processor and to manage outgoing memory access requests routed to the cache using the plurality of abstraction layers.

Layered architecture for hybrid controller

Incoming memory access requests are routed in a set of incoming queues, the incoming memory access requests comprise a range of host logical block addresses (LBAs) that correspond to a memory space of a primary memory. The host LBA range is mapped to clusters of secondary memory LBAs, the secondary memory LBAs corresponding to a memory space of a secondary memory. Each incoming memory access request queued in the set of incoming queues is transformed into one or more outgoing memory access requests that include a range of secondary memory LBAs or one or more clusters of secondary memory LBAs. The outgoing memory access requests are routed in a set of outgoing queues. The secondary memory is accessed using the outgoing memory access requests.

Memory access requests in hybrid memory system

A host read request affects a request address range of a main storage. A speculative address range proximate to the request address range is defined. Speculative data stored in the speculative address range is not requested via the host read request. A criterion is determined that is indicative of future read requests of associated with the speculative data. The speculative data is copied from the main storage to at least one of a non-volatile cache and a volatile cache together with data of the host read request in response to the criterion meeting a threshold. The non-volatile cache and the volatile cache mirror respective portions of the main storage.

Defining address ranges used to cache speculative read data

Momentary contact with a defect site of a data storage disk or free particle by a magnetoresistive read element of a flying head causes momentary heating and unwanted increase in element resistance (thermal asperity) which can disrupt hard disk drive data reading operations. Since the disk carries a predetermined data format, the disk drive controller correlates location of a thermal asperity to the format and thereupon selects from several available thermal asperity recovery methods a method most likely to minimize thermal asperity effect upon disk drive operation during rereading of data at the thermal asperity location.

Growing community of inventors

Sterling, MA, United States of America

James David Sawin