Rate limit on the transitions of zones to open

Patent metadata

Field	Value
Publication number	US-11640266-B2
Application number	US-202117465391-A
Country	US
Kind code	B2
Filing date	Sep 2, 2021
Priority date	May 27, 2020
Publication date	May 2, 2023
Grant date	May 2, 2023

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. The controller restricts the host to a maximum number of zones that can be in the open and active state at a time. Open zones can be switched to the closed state, and vice versa, upon a predetermined amount of time expiring. The maximum number of open zones is based on one or more amounts of time to: generate parity data, copy the parity data from the RAM2 to the RAM1, update the parity data, switch a zone from the open and active state to the closed state, and the amount of space in a temporary RAM1 buffer.

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;
a first volatile memory unit having a first plurality of storage regions; and
a controller coupled to the non-volatile storage unit and the first volatile memory unit, the controller comprising a second volatile memory unit having a second plurality of regions, wherein the controller is configured to:
write old first parity data to a first region of the first plurality of regions;
update the old first parity data in a second region of the first plurality of regions to create new first parity data; and
copy the new first parity data to a first region of the second plurality of regions.

2. The storage device of claim 1 , wherein the controller is further configured to set a maximum number of open and active zones.

3. The storage device of claim 1 , wherein the controller is further configured to receive one or more first commands to write data to one or more open and active zones of the plurality of zones.

4. The storage device of claim 1 , wherein the controller is further configured to receive one or more second commands to write data to a first zone, wherein the first zone is in a closed or resource conserved lower performance internal state.

5. The storage device of claim 4 , wherein the controller is further configured to change a least recently used open and active zone to the closed or resource conserved lower performance internal state.

6. The storage device of claim 5 , wherein the controller is further configured to change the first zone to an open and active state.

7. The storage device of claim 6 , wherein the controller is further configured to determine which open and active zone was least recently used prior to changing the least recently used open and active zone to the closed or resource conserved lower performance internal state.

8. The storage device of claim 1 , wherein the second volatile memory is a SRAM unit and the first volatile memory is a DRAM unit.

9. 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;
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 controller is configured to:
receive one or more commands to write data to a closed first zone of the plurality of zones;
determine which open and active zone of the plurality of zones is a least recently used zone of the open and active zones upon receiving one or more commands;
close the least recently used zone;
open the closed first zone; and
write the data to the opened first zone.

10. The storage device of claim 9 , wherein a maximum number of open and active zones is determined based on an amount of time it takes to change the least recently used zone to the closed or resource conserved lower performance internal state and to change the first zone to an open and active state.

11. The storage device of claim 10 , wherein the controller is further configured to change the least recently used zone to the closed or resource conserved lower performance internal state only after a predetermined amount of time has expired.

12. The storage device of claim 9 , wherein the controller comprises one or more controller buffer regions, and wherein the one or more commands received to write data to the closed first zone of the plurality of zones fill the one or more controller buffer regions to capacity.

13. The storage device of claim 9 , wherein a maximum number of open and active zones is determined based on a number of temporary locations in the second volatile memory unit.

14. The storage device of claim 9 , wherein the controller is further configured to adjust a location of a write pointer for an open and active zone.

15. The storage device of claim 9 , wherein the controller is further configured to reset a write pointer to a zone start logical block address.

16. 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;
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, the second volatile memory comprising one or more temporary locations, wherein the controller is configured to:
set a maximum number of open and active zones, wherein the maximum number of open and active zones is determined based on a number of temporary locations in the second volatile memory, wherein the maximum number of open and active zones is further determined based on an amount of time for generating new first parity data, copying previous first parity data, and updating the previous first parity data takes, and an amount of time it takes to change another open and active zone to a closed or resource conserved lower performance internal state and to change the closed zone to an open and active state.

17. The storage device of claim 16 , wherein the controller is configured to:
receive one or more first commands to write data to one or more open and active zones of the plurality of zones;
generate the new first parity data for a first open and active zone in a first temporary location in the second volatile memory unit;
change a second open and active zone to the closed or resource conserved lower performance internal state upon receiving one or more second commands to write data to a closed zone; and
change the closed zone to an open and active state.

18. The storage device of claim 17 , wherein the controller is further configured to:
copy previous first parity data for the first open and active zone from the first volatile memory unit to a first location in the second volatile memory unit while generating the new first parity data; and
update the previous first parity data with the new first parity data in the second volatile memory unit.

19. The storage device of claim 17 , wherein the controller is further configured to determine that the second open and active zone is the open and active zone that was least recently used.

20. The storage device of claim 16 , wherein the controller is further configured to change an open and active zone to the closed or resource conserved lower performance internal state after a predetermined amount of time has expired, wherein the predetermined amount of time is about 0.5 seconds to about 5 seconds, and wherein the maximum number of open and active zones is further determined based on the predetermined amount of time.

Assignees

• Western Digital Tech Inc

Inventors

• Parker Liam
• Helmick Daniel L
• Gorobets Sergey Anatolievich

Classifications

• G06F3/0619

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

• G06F3/0644

  Management of space entities, e.g. partitions, extents, pools · CPC title

• G06F3/0656

  Data buffering arrangements · CPC title

• G06F3/0679

  Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP] · CPC title

• G06F3/0659 Primary

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