Systems and methods for identifying storage resources that are not in use

• US 10,387,327 B2
• Filed: 08/04/2016
• Issued: 08/20/2019
• Est. Priority Date: 12/06/2006
• Status: Active Grant

• Current Assignee: Unification Technologies LLC (Acacia Research Corporation)
• Original Assignee: FIO Semiconductor Technologies, LLC (Inception Holdings, LLC)
• Inventors: Flynn, David, Thatcher, Jonathan, Zappe, Michael
• Primary Examiner(s): Dudek, Jr., Edward J
• Application Number:
  US15/228,893
• Publication Number:
  US 20160342366A1
• Time in Patent Office: 1,111 Days
• CPC Class Codes: G06F 1/183 Internal mounting support structures, e.g. for printed circuit boards, internal connecting means for buses G06F13/409
• CPC Class Codes: G06F 11/108 Parity data distribution in semiconductor storages, e.g. in SSD
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/0804 with main memory updating G06F12/0806 takes precedence
• 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 12/12 Replacement control
• CPC Class Codes: G06F 12/121 using replacement algorithms
• CPC Class Codes: G06F 12/123 with age lists, e.g. queue, most recently used [MRU] list or least recently used [LRU] list
• CPC Class Codes: G06F 13/28 using burst mode transfer, e.g. direct memory access DMA, cycle steal G06F13/32 takes precedence
• CPC Class Codes: G06F 13/4022 using switching circuits, e.g. switching matrix, connection or expansion network G06F13/4009 takes precedence
• CPC Class Codes: G06F 13/426 using an embedded synchronisation, e.g. Firewire bus, Fibre Channel bus, SSA bus
• CPC Class Codes: G06F 2211/002 Bus
• CPC Class Codes: G06F 2211/103 Hybrid, i.e. RAID systems with parity comprising a mix of RAID types
• CPC Class Codes: G06F 2212/1032 Reliability improvement, data loss prevention, degraded operation etc
• CPC Class Codes: G06F 2212/1044 Space efficiency improvement
• CPC Class Codes: G06F 2212/2022 Flash memory
• CPC Class Codes: G06F 2212/222 Non-volatile memory
• CPC Class Codes: G06F 2212/70 Details relating to dynamic memory management
• CPC Class Codes: G06F 2212/7203 Temporary buffering, e.g. using volatile buffer or dedicated buffer blocks
• CPC Class Codes: G06F 2212/7205 Cleaning, compaction, garbage collection, erase control
• CPC Class Codes: G06F 2212/7208 : Multiple device management, e.g. distributing data over multiple flash devices
• CPC Class Codes: G06F 3/0604 : Improving or facilitating administration, e.g. storage management
• CPC Class Codes: G06F 3/0608 : Saving storage space on storage systems
• CPC Class Codes: G06F 3/0613 : in relation to throughput
• CPC Class Codes: G06F 3/0619 : in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0643 : Management of files
• CPC Class Codes: G06F 3/065 : Replication mechanisms
• CPC Class Codes: G06F 3/0652 : Erasing, e.g. deleting, data cleaning, moving of data to a wastebasket
• CPC Class Codes: G06F 3/0656 : Data buffering arrangements
• 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]
• CPC Class Codes: G06F 3/0685 : Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays
• CPC Class Codes: G06F 3/0688 : Non-volatile semiconductor memory arrays
• CPC Class Codes: G06F 9/52 : Program synchronisation; Mutual exclusion, e.g. by means of semaphores
• CPC Class Codes: G06F 9/54 : Interprogram communication
• CPC Class Codes: H04L 67/02 : based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/1097 : for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: H05K 7/1444 : Complex or three-dimensional-arrangements; Stepped or dual mother boards
• CPC Class Codes: H05K 7/1487 : Blade assemblies, e.g. blade cases or inner arrangements within a blade
• CPC Class Codes: Y02D 10/00 : Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

An apparatus, system, and method are disclosed for managing a non-volatile storage medium. A storage controller receives a message that identifies data that no longer needs to be retained on the non-volatile storage medium. The data may be identified using a logical identifier. The message may comprise a hint, directive, or other indication that the data has been erased and/or deleted. In response to the message, the storage controller records an indication that the contents of a physical storage location and/or physical address associated with the logical identifier do not need to be preserved on the non-volatile storage medium.

Claims

1. A method for managing data in a NAND flash storage system, the method comprising:

sending, by a host processor, an empty-block directive including a logical identifier comprising data deleted by the host processor;

receiving, at a solid-state storage controller maintaining a block mapping table between logical identifiers and physical storage locations of the NAND flash memory, the empty block directive including the logical identifier, wherein the logical identifier is associated, in the block mapping table, with a physical storage location comprising data deleted by the host processor;

updating, by the solid state storage controller, the block mapping table to indicate that the physical storage location associated with the logical identifier comprises data deleted by the host;

sending, by the host processor, a read command requesting to read data associated with the logical identifier included in the empty block directive; and

returning, from the solid-state storage controller to the host processor, a data string comprising data of a predetermined logic level, based on the updated block mapping table, in response to the read command requesting to read data associated with the logical identifier included in the empty block directive, wherein the data of the predetermined logic level indicates that the data associated with the logical block identifier is deleted.

2. The method of claim 1 wherein the predetermined logic level is zero.

3. The method of claim 1 further comprising:

determining that the empty-block directive further includes an indication that data associated with the logical identifier should be overwritten; and

overwriting the data associated with the logical identifier.

4. The method of claim 1 wherein the empty-block directive is part of a block storage protocol.

5. The method of claim 1 wherein the empty-block directive is received through an application programming interface.

6. The method of claim 1 wherein the empty-block directive is received from a file system.

7. The method of claim 1, wherein the empty-block directive is received from a storage client.

8. The method of claim 1, further comprising performing garbage collection on storage locations in the flash storage system.

9. The method of claim 8, wherein performing garbage collection comprises:

copying a block containing data to be preserved from an erase block, wherein the erase block comprises at least one block containing data to be preserved and blocks containing data that do not need to be preserved, and

erasing data from the erase block.

10. The method of claim 9, further comprising writing new data to the erased erase block.

11. The method of claim 1, wherein the NAND flash storage system is an append-only storage system.

12. A system, comprising:

a host processor configured to;

send an empty block directive, wherein the empty block directive includes a logical identifier for data to be deleted; and

send a read command requesting to read data associated with a logical identifier;

a NAND flash memory; and

a solid-state storage controller configured to;

maintain a block mapping table between logical identifiers and physical storage locations of the NAND flash memory;

receive an empty-block directive from the host processor, the empty block directive including a logical block identifier associated, in the block mapping table, with one or more physical storage locations of the NAND flash memory;

update the block mapping table to indicate that the one or more locations comprise data deleted by the host;

return, from the solid-state storage controller to the host processor, a data string comprising data of a predetermined logic level, based on the updated block mapping table, in response to a read command requesting to read data associated with the logical block identifier, wherein the data of the predetermined logic level indicates that the data associated with the logical block identifier is deleted.

13. The system of claim 12, wherein the predetermined logic level is zero.

14. The system of claim 12, wherein the storage controller is further configured to:

determine that the empty-block directive includes an indication that data associated with the block identifier should be overwritten; and

overwrite the data associated with the block identifier.

15. The system of claim 12, wherein the empty-block directive is part of a block storage protocol.

16. The system of claim 12, wherein the empty-block directive is received through an application programming interface.

17. The system of claim 12, wherein the empty-block directive is received from a file system.

18. The system of claim 12, wherein the empty-block directive is received from a storage client.

19. The system of claim 12, wherein the storage controller is further configured to perform garbage collection on storage locations in the NAND flash memory.

20. The system of claim 12, wherein the system is an append-only storage system.