Micron Technology Incorporated

Sandisk Technologies Inc.

Oplink Communications, Inc.

Huapeng G Guan

Yipei Yu

Wei Wang

Jiangli Zhu

Frederick Adi

Venkata Naga Lakshman Pasala

Aaron Keith Olbrich

Anand Kulkarni

Douglas Alan Prins

Jenkin Angelo Richard

Eric V Chamness

Steven R Narum

Ximin Shan

Graeme Weston-Lewis

A memory device may detect a memory operation that updates a level two volatile (L2V) entry stored in an L2V table. Each L2V entry in the L2V table may indicate a mapping between a respective logical block address (LBA) and a respective user data physical address in non-volatile memory. The memory operation may cause a mapping between an LBA indicated in the L2V entry and a user data physical address indicated in the L2V entry to become invalid. The memory device may store, in a volatile memory log, an indication of an LBA region that includes the LBA. The memory device may detect that an L2 transfer condition, associated with the volatile memory log, is satisfied. The memory device may copy, from volatile memory to non-volatile memory, every L2V entry that indicates an LBA included in the LBA region based on detecting that the L2 transfer condition is satisfied.

Logical to physical (L2P) address mapping with fast L2P table load times

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.

Tracking intermix of writes and un-map commands across power cycles

A low cost compact 3-port single-channel OADM with improved optical isolation is provided in which the I/O fibers and add/drop fiber are arranged on the same side. The 3-port OADM includes a 3-fiber pigtail and an angled reflector that together eliminate the second fiber collimator&#x2014;one set of lenses and ferrules. The reflector is positioned behind and at angle to the free-space filter such that the add/drop optical signals are reflected back through the collimating lens to the appropriate fiber. In a drop filter, a signal is dropped from the optical signal on the input fiber and reflected back to the add/drop fiber. In an add filter, a signal is inserted from the add/drop fiber and reflected back to the output fiber. A 4-port OADM can be made by fiber-splicing a pair of 3-port OADMs.

Growing community of inventors

Redwood City, CA, United States of America

Huapeng G Guan