Method and apparatus for providing a shared nonvolatile memory system using a distributed FTL scheme

• US 9,952,788 B2
• Filed: 09/28/2016
• Issued: 04/24/2018
• Est. Priority Date: 09/29/2015
• Status: Active Grant

• Current Assignee: Point Financial, Inc.
• Original Assignee: Cnex Labs, Inc.
• Inventors: Huang, Yiren Ronnie
• Primary Examiner(s): Dudek, Jr., Edward J
• Assistant Examiner(s): Verderamo, III, Ralph A
• Application Number:
  US15/278,833
• Publication Number:
  US 20170090794A1
• Time in Patent Office: 573 Days
• Field of Search: None
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/0815 Cache consistency protocols
• CPC Class Codes: G06F 12/0868 Data transfer between cache memory and other subsystems, e.g. storage devices or host systems
• CPC Class Codes: G06F 2212/1032 Reliability improvement, data loss prevention, degraded operation etc
• CPC Class Codes: G06F 2212/214 Solid state disk
• CPC Class Codes: G06F 2212/261 Storage comprising a plurality of storage devices
• CPC Class Codes: G06F 2212/284 being distributed
• CPC Class Codes: G06F 2212/466 Metadata, control data
• CPC Class Codes: G06F 2212/7201 Logical to physical mapping or translation of blocks or pages
• CPC Class Codes: G06F 2212/7208 Multiple device management, e.g. distributing data over multiple flash devices
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0637 Permissions
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]

Abstract

One embodiment of the present invention discloses a shared non-volatile memory (“NVM”) system using a distributed flash translation layer (“FTL”) scheme capable of facilitating data storage between multiple hosts and NVM devices. A process of shared NVM system includes an NVM management module or memory controller able to receive a request from a host for reserving a write ownership. The write ownership allows a host to write information to a portion of storage space in an NVM device. Upon identifying availability of the write ownership associated with the NVM device in accordance with a set of predefined policy stored in the NVM management module, the request is granted to the host if the write ownership is available. The host is subsequently allowed to fetch the FTL snapshot from the NVM device for the write operation.

Claims

1. A method for providing a shared non-volatile memory (“

NVM”

) system, comprising;

receiving, by an NVM management module, a first request from a first host for reserving a write ownership for allowing the first host to write information to a portion of storage space in a first NVM device;

identifying availability of the write ownership associated with the first NVM device in accordance with a set of predefined policy stored in the NVM management module;

granting the first request to the first host if the write ownership of the first NVM device is available for reserve; and

allowing the first host to fetch a flash translation layer (“

FTL”

) snapshot from the first NVM device.

2. The method of claim 1, further comprising loading FTL index table for IO write and mapping logic block address (“

LBA”

) to NVM physical address.

3. The method of claim 1, further comprising allowing the first host to write information to the portion of storage space in the first NVM device.

4. The method of claim 3, further comprising modifying locally stored FTL snapshot in accordance with the information stored in the portion of storage space in the first NVM device.

5. The method of claim 4, further comprising sending a notice from the first host to the NVM management module to indicate a completion of write operation when writing is finished.

6. The method of claim 5, further comprising instructing the first host to replace the FTL snapshot in the first NVM device with the locally stored FTL snapshot in the first host.

7. The method of claim 6, further comprising broadcasting by the NVM management module a message to other hosts indicating that the first NVM device contains an updated FTL snapshot.

8. The method of claim 1, wherein receiving, by an NVM management module, a first request from a first host includes forwarding a first IO write reservation from the first host to the NVM controller via a switching fabric.

9. The method of claim 1, wherein identifying availability of the write ownership associated with the first NVM device includes searching through a reservation table stored in the NVM management module to determine whether the write ownership has been reserved by other hosts.

10. The method of claim 1, wherein identifying availability of the write ownership associated with the first NVM device includes allowing the first host to load a spare version of FTL snapshot from the first NVM device when current reservation for write ownership is not available to the first host.

11. The method of claim 1, further comprising:

receiving a second request from a second host for reserving a write ownership for allowing the second host to write information to a portion of storage space in a second NVM device;

identifying availability of the write ownership associated with the second NVM device in accordance with a set of predefined policy stored in the NVM management module;

granting the second request to the second host if the write ownership is available for reserve; and

allowing the second host to fetch a FTL snapshot from the second NVM device.

12. A shared non-volatile memory (“

NVM”

) system configured to store information persistently, comprising;

a plurality of hosts, able to process and store data, configured to provide interfaces with a plurality of users;

a switching fabric coupled to the plurality of hosts and configured to provide connections;

a plurality of NVM devices coupled to the switching fabric and configured to store information persistently; and

an NVM management module coupled to the switching fabric and configured to manage granting of write ownerships associated with the plurality of NVM devices, which allows a flash translation layer (FTL) snapshot to be fetched by one of the plurality of hosts from one of the plurality of NVM devices, in response to a plurality of requests initiated by the plurality of hosts.

13. The system of claim 12, wherein the plurality of hosts includes computers, laptops, portable devices, servers, or smartphones.

14. The system of claim 12, wherein the switching fabric includes interconnections between NVM devices and hosts and the plurality of NVM devices includes flash memory devices.

15. The system of claim 12, wherein the NVM management module is a memory controller capable of providing write control and read access to the plurality of NVM devices.

16. The system of claim 12, wherein the NVM management module is a memory controller capable of providing read access associated with the plurality of NVM devices in response to a plurality of requests initiated by the plurality of hosts.

17. The system of claim 12, wherein the NVM management module is configured to facilitate a shared NVM storage between multiple hosts utilizing a distributed flash translation layer (“

FTL”

) cache scheme.

18. A method for providing a shared non-volatile memory (“

NVM”

) system, comprising;

receiving a read request from a first host via a network requesting a read access to a first portion of storage space in a first NVM device;

identifying accessibility of read access associated with the first NVM device in accordance with a set of predefined read policy stored in a memory controller;

receiving a write request from a second host for reserving a write ownership for allowing the second host to write information to a second portion of storage space in the first NVM device;

identifying availability of the write ownership associated with the first NVM device in accordance with a set of predefined write policy stored in the memory controller; and

granting the write request to the second host based and allowing the second host to update a spare version of flash translation layer (“

FTL”

) snapshot from the first NVM device when the first NVM device is accessed by the first host.

19. The method of claim 18, further comprising instructing the second host to replace the FTL snapshot in the first NVM device with the locally stored FTL snapshot in the second host.

20. The method of claim 18, further determining the availability of the write ownership associated with the first NVM device in accordance with status associated with the first NVM device recorded in a status table in the memory controller.