Micron Technology Incorporated

Sandisk Technologies Inc.

Yipei Yu

Huapeng G Guan

Wei Wang

Jiangli Zhu

Frederick Adi

Venkata Naga Lakshman Pasala

Aaron Keith Olbrich

Anand Kulkarni

Douglas Alan Prins

Ximin Shan

Graeme Weston-Lewis

A system for managing power loss can include a number of memory devices including a volatile memory device and a non-volatile memory device and a processing device operatively coupled with the plurality of memory devices. The processor can save a snapshot of a logical-to-physical (L2P) table to a non-volatile memory device and maintain a journal of updates of the L2P. The processor can retrieve a sequence number from system metadata and save the most recent set of updates of the L2P table to a dedicated area of the non-volatile memory device, where the dedicated area is identified by the sequence number.

Managing power loss in a memory device

A system for managing power loss can include a number of memory devices including a volatile memory device and a non-volatile memory device and a processing device operatively coupled with the plurality of memory devices. The processor can save a snapshot of a logical-to-physical (L2P) table to a non-volatile memory device and maintain a journal of updates of the L2P. The processor can, in response to a parameter of journal buffer of a volatile memory device satisfying a threshold criterion, save at least one journal of updates of the L2P table to the non-volatile memory device. It can also retrieve a sequence number from system metadata and save the most recent set of updates of the L2P table to a dedicated area of the non-volatile memory device, where the dedicated area is identified by the sequence number, in response to detecting a power loss event.

A system for file system data access can include memory devices including a non-volatile memory device, as well as a processing device, operatively coupled with the memory devices to perform operations including receiving a file system (FS) write command and determining whether a write count of a physical super management unit (PSMU) of the non-volatile memory device satisfies a threshold criterion. The operations can include, recording a change of a super management unit (SMU) mapping for FS data of an FS mapping table, where the FS mapping table is a portion of a logical-to-physical (L2P) mapping table and performing a move of SMU data corresponding to the change of the SMU mapping. They can also include creating a backup copy of the FS mapping table on the non-volatile memory device, and restoring the FS mapping table from the backup copy of the FS mapping table.

Rapid reliable file system access

An example memory sub-system includes one or more memory devices and a processing device, operatively coupled to the one or more memory devices. The processing device is configured to store, on a non-volatile memory device of the one or more memory devices, a snapshot of a logical-to-physical (L2P) table comprising a plurality of L2P table entries, each L2P table entry mapping a logical address defined in a logical address space to a physical address identifying a management unit on a memory device of the one or more memory devices; store, on the non-volatile memory device of the one or more memory devices, a physical-to-logical (P2L) table comprising a plurality of P2L table entries, each L2P table entry mapping a physical address identifying a management unit on a memory device of the one or more memory devices to metadata associated with the management unit; store, on the non-volatile memory device, a list of unallocated MUs; store, on the non-volatile memory device, an L2P update journal including one or more L2P journal entries, wherein each L2P journal entry reflects an update to an L2P table entry of the plurality of L2P table entries, wherein the update has been performed after storing the snapshot of the L2P table; and responsive to detecting a power up event following a power loss event, reconstruct the L2P table using the snapshot of the L2P table, the L2P update journal, the P2L table, and the list of unallocated management units.

Power loss recovery for memory devices

Systems, methods and/or devices are used to enable tracking intermix of writes and un-map commands across power cycles. In one aspect, the method includes (1) receiving, at a storage device, a plurality of commands from a host, the storage device including non-volatile memory, (2) maintaining a log corresponding to write commands and un-map commands from the host, (3) maintaining a mapping table in volatile memory, the mapping table used to translate logical addresses to physical addresses, (4) saving the mapping table, on a scheduled basis that is independent of the un-map commands, to the non-volatile memory of the storage device, (5) saving the log to the non-volatile memory, and (6) upon power up of the storage device, rebuilding the mapping table from the saved mapping table in the non-volatile memory of the storage device and from the saved log in the non-volatile memory of the storage device.

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San Francisco, CA, United States of America

Yipei Yu