Dynamic use of segment or zone power loss protection in a flash device

Patent metadata

Field	Value
Publication number	US-11416144-B2
Application number	US-202117235062-A
Country	US
Kind code	B2
Filing date	Apr 20, 2021
Priority date	Dec 12, 2019
Publication date	Aug 16, 2022
Grant date	Aug 16, 2022

Abstract

A storage system and related method are for operating solid-state storage memory in a storage system. Zones of solid-state storage memory are provided. Each zone includes a portion of the solid-state storage memory. The zone has a data write requirement for the zone for reliability of data reads. The storage system adjusts power loss protection for at least one zone. The adjusting is based on the data write requirement for the zone and responsive to detecting a power loss.

First claim

What is claimed is:

1. A method, comprising:
providing a plurality of zones of solid-state storage memory, each zone comprising a portion of the solid-state storage memory and having a data write requirement associated with respective zone for reliability of data reads;
tracking whether each zone is an open zone having one or more non-durable data segments or a closed zone having one or more durable data segments;
adjusting power loss protection for at least one zone, the adjusting based on the data write requirement for the at least one zone and responsive to detecting a power loss, and
revoking a credit that was issued and applied in activating the power loss protection for a zone, to deactivate the power loss protection for the zone.

2. The method of claim 1 , further comprising:
closing each open segment of solid-state storage memory in a zone that has the power loss protection activated, responsive to the detecting the power loss.

3. The method of claim 1 , further comprising:
issuing one or more credits for activating the power loss protection for one or more zones.

4. The method of claim 1 , wherein the providing the plurality of zones comprises:
issuing a determined amount of credits for the power loss protection of the zones, wherein the determined amount of credits is based on amount of cache memory for data transfers to the solid-state storage memory during power loss.

5. The method of claim 1 , further comprising:
determining an amount of credits for the power loss protection of the zones, based on determination of available time duration for power loss support as a dynamic determination over a life span of the storage system.

6. The method of claim 1 , wherein the providing the plurality of zones comprises:
tracking how many zones having the power loss protection enabled that a garbage collection process is allowed to use.

7. The method of claim 1 , wherein the providing the plurality of zones comprises:
defining zones as each zone is written with data writes.

8. The method of claim 1 , wherein the providing the plurality of zones comprises:
tracking open zones of the plurality of zones to limit an amount of open zones to have the power loss protection enabled in accordance with available amount of power loss support.

9. The method of claim 1 , wherein the providing the plurality of zones comprises:
providing credits for the power loss protection, with each of a plurality of processes, each of the plurality of processes arranged to hold or apply one or more of the credits.

10. A tangible, non-transitory, computer-readable media having instructions thereupon which, when executed by a processor, cause the processor to perform a method comprising:
defining a plurality of zones of solid-state storage memory, each zone comprising a portion of the solid-state storage memory having a data write requirement for the zone, the data write requirement associated with reliability of data reads;
tracking whether each zone is an open zone having one or more non-durable data segments or a closed zone having one or more durable data segments;
monitoring power loss protection activation for each zone, the power loss protection comprising arranging to fulfill the data write requirement for the zone, and
revoking a credit that was issued and applied in activating the power loss protection for a zone, to deactivate the power loss protection for the zone.

11. The computer-readable media of claim 10 , wherein the method further comprises:
determining an amount of open zones having the power loss protection activated.

12. The computer-readable media of claim 10 , wherein the tracking comprises:
issuing a credit to a process to activate the power loss protection for a zone.

13. The computer-readable media of claim 10 , wherein the tracking comprises:
determining an amount of credits for the power loss protection of the zones, based on amount of cache memory for data transfers to the solid-state storage memory during power loss or available time duration for the power loss.

14. The computer-readable media of claim 10 , wherein the method further comprises:
performing garbage collection in the solid-state storage memory, with an amount of open zones having the power loss protection enabled limited based on available amount of power loss support.

15. A storage system, comprising:
solid-state storage memory having a plurality of zones, each zone comprising a portion of the solid-state storage memory having a data write requirement for the zone for reliability of data reads; and
a processing device, to:
track, in a data structure, each of the plurality of zones, including indicating open zones having one or more non-durable data segments and closed zones having one or more durable data segments that fulfill the data write requirement for the zone in the solid-state storage memory;
monitor power loss protection activation for each zone, the power loss protection comprising arranging to fulfill the data write requirement for the zone, in event of power loss; and
revoking a credit that was issued and applied in activating the power loss protection for a zone, to deactivate the power loss protection for the zone.

16. The storage system of claim 15 , wherein the processing device is further to:
close each open zone that has the power loss protection activated, fulfilling the data write requirement for the zone, responsive to the power loss occurring.

17. The storage system of claim 15 , wherein the processing device is further to:
manage credits for activating the power loss protection, limited to an amount of credits based on amount of cache memory for data transfers to the solid-state storage memory during the power loss or available time duration for power loss support.

18. The storage system of claim 15 , wherein the processing device is further to:
monitor how many open zones having the power loss protection enabled that a garbage collection process is allowed to use.

19. The storage system of claim 15 , further comprising the processing device to track, in the data structure, credits for the power loss protection, wherein an open zone has the power loss protection enabled with a credit tracked in the data structure and a closed zone is a durable zone where the power loss protection is disabled.

Assignees

• Pure Storage Inc

Inventors

• Bernat Andrew R
• Davis Brandon
• Mcauliffe Mark L
• Dewitt Zoltan
• Scholbrock Benjamin
• Hord Phillip
• Karr Ronald

Classifications

• G06F12/0246

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

• G06F12/0253

  Garbage collection, i.e. reclamation of unreferenced memory · CPC title

• G06F3/0623

  in relation to content · CPC title

• G06F11/108

  Parity data distribution in semiconductor storages, e.g. in SSD · CPC title

• G06F2212/7205

  Cleaning, compaction, garbage collection, erase control · CPC title