Data integrity protection of ZNS needs

Patent metadata

Field	Value
Publication number	US-11520523-B2
Application number	US-202016883916-A
Country	US
Kind code	B2
Filing date	May 26, 2020
Priority date	May 26, 2020
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

The present disclosure generally relates to methods of operating storage devices. The storage device comprises a controller comprising first random access memory (RAM1), second random access memory (RAM2), and a storage unit divided into a plurality of zones. When a write command is received to write data to a zone, change log data is generated and stored in the RAM1, the previous delta data for the zone is copied from the RAM2 to the RAM1 to be updated with the change log data, and the updated delta data is copied to the RAM2. The delta data stored in the RAM2 is copied to the storage unit periodically. The controller tracks which delta data has been copied to the RAM2 and to the storage unit. During a power failure, the delta data and the change log data are copied from the RAM1 or the RAM2 to the storage unit.

First claim

What is claimed is:

1. A storage device, comprising:
a non-volatile storage unit, wherein a capacity of the non-volatile storage unit is divided into a plurality of zones, and wherein the non-volatile storage unit comprises a plurality of dies, each of the plurality of dies comprising a plurality of erase blocks, and wherein each zone of the plurality of zones comprises a plurality of erase blocks;
a first volatile memory unit; and
a controller coupled to the non-volatile storage unit and the first volatile memory unit, the controller comprising a second volatile memory unit, wherein the second volatile memory unit comprises one or more temporary storage regions and a plurality of non-temporary storage regions, and wherein the controller is configured to:
receive one or more commands to write data to a first zone of the plurality of zones;
generate change log data for the first zone in a first temporary storage region of the one or more temporary storage regions in the second volatile memory unit;
copy previously written delta data for the first zone from the first volatile memory unit to a first non-temporary storage region of the plurality of non-temporary storage regions of the second volatile memory unit upon receiving the one or more commands to write data to the first zone;
update the previously written delta data with the change log data in the first non-temporary storage region; and
copy the change log data for the first zone to the non-volatile storage unit upon experiencing a power failure event while updating the previously written delta data with the change log data.

2. The storage device of claim 1 , wherein the controller is further configured to:
copy the updated delta data from the second volatile memory unit to the first volatile memory unit; and
copy the updated delta data from the second volatile memory unit to the non-volatile storage unit.

3. The storage device of claim 2 , wherein the controller is further configured to:
track whether the previously written delta data has been updated with the change log data; and
copy the change log data to the non-volatile storage unit responsive to the previously written delta data having not yet been updated with the change log data.

4. The storage device of claim 1 , further comprising one or more energy storage devices configured to provide power to the controller, wherein the controller is further configured to use the power provided by the one or more energy storage devices to copy the change log data for the first zone to the non-volatile storage unit upon experiencing the power failure event.

5. The storage device of claim 1 , wherein the first volatile memory unit is configured to store a first logical to physical address table, the first logical to physical address table associating logical block addresses of data to a physical address of where the data is stored in the non-volatile storage unit.

6. The storage device of claim 5 , wherein the controller is further configured to:
partition the first logical to physical address table into sections having a partitioned section size; and
update a second logical to physical address table stored in the non-volatile storage unit, wherein the second logical to physical address table is updated in the partitioned section size.

7. A storage device, comprising:
a non-volatile storage unit, wherein a capacity of the non-volatile storage unit is divided into a plurality of zones, and wherein the non-volatile storage unit comprises a plurality of dies, each of the plurality of dies comprising a plurality of erase blocks, and wherein each zone of the plurality of zones comprises a plurality of erase blocks;
a first volatile memory unit comprising a plurality of ranks, wherein the plurality of ranks are divided into one or more sections; and
a controller coupled to the non-volatile storage unit and the first volatile memory unit, the controller comprising a second volatile memory unit, wherein the second volatile memory unit comprises one or more temporary storage regions and a plurality of non-temporary storage regions, and wherein the controller is configured to:
receive one or more write commands to write data to one or more zones of the plurality of zones;
update delta data associated with at least one zone of the one or more zones for each of the one or more write commands received in a temporary storage region of the one or more temporary storage regions of the second volatile memory unit, wherein delta data is updated for a particular zone each time a command is received to write data to the particular zone;
copy the updated delta data associated with the at least one zone from the temporary storage region of the second volatile memory unit to the plurality of ranks of the first volatile memory unit; and
copy the one or more sections of the plurality of ranks of the first volatile memory unit to the non-volatile storage unit, wherein one section of the one or more sections is copied to the non-volatile storage unit at a time upon a predetermined amount of time expiring.

8. The storage device of claim 7 , wherein the controller is further configured to copy the updated delta data from the first volatile memory unit to a parking section in the non-volatile storage unit.

9. The storage device of claim 7 , wherein the predetermined amount of time is about 20 seconds.

10. The storage device of claim 7 , wherein each of the one or more sections is copied to the non-volatile storage about once per minute.

11. The storage device of claim 7 , further comprising one or more energy storage devices configured to provide power to the controller, wherein the controller is further configured to use the power provided by the one or more energy storage devices to copy the one or more sections of the plurality of ranks of the first volatile memory unit to the non-volatile storage unit upon experiencing a power failure event.

12. The storage device of claim 7 , wherein the controller is further configured to:
copy previously written delta data associated with the at least one zone from the first volatile memory unit to a non-temporary storage region of the plurality of non-temporary storage regions of the second volatile memory unit upon receiving the one or more commands; and
generate change log data associated with the at least one zone for each of the one or more write commands received in a temporary storage region of the one or more temporary storage regions of the second volatile memory unit, wherein updating the delta data associated with the at least one zone comprises updating the previously written delta data with the change log data in the non-temporary storage region.

13. The storage device of claim 7 , wherein the first volatile memory unit is dynamic random-access memory (DRAM) or magnetoresistive random-access memory (MRAM).

14. A storage device, comprising:
a non-volatile storage unit, wherein a capacity of the non-volatile storage unit is divided into a plurality of zones, and wherein the non-volatile storage unit comprises a plurality of dies, each of the plurality of dies comprising a plurality of erase blocks, and wherein each zone of the plurality of zones comprises a plurality of erase blocks;
a first volatile memory unit comprising a plurality of ranks, wherein the plurality of ranks are divided into one or more sections; and
a controller coupled to the non-volatile storage unit and the first volatile memory unit, the controller comprising a second volatile memory unit, wherein the second volatile memory unit comprises one or more temporary storage regions and a plurality of non-temporary storage re

Assignees

• Western Digital Tech Inc

Inventors

• Helmick Daniel L
• Grayson Peter

Classifications

• G06F12/0246

  in block erasable memory, e.g. flash memory · CPC title

• G06F3/0629

  Configuration or reconfiguration of storage systems · CPC title

• G06F1/30

  Means for acting in the event of power-supply failure or interruption, e.g. power-supply fluctuations (for resetting only G06F1/24) · CPC title

• G06F3/0619

  in relation to data integrity, e.g. data losses, bit errors · CPC title

• G06F3/0659 Primary

  Command handling arrangements, e.g. command buffers, queues, command scheduling · CPC title