APPARATUS, SYSTEM, AND METHOD FOR SOLID-STATE STORAGE AS CACHE FOR HIGH-CAPACITY, NON-VOLATILE STORAGE

• US 20090132760A1
• Filed: 12/06/2007
• Published: 05/21/2009
• Est. Priority Date: 12/06/2006
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: Fusion-IO Incorporated (Western Digital Corporation)
• Inventors: Zappe, Michael, Flynn, David, Thatcher, Jonathan, Strasser, John
• Granted Patent: US 8,019,938 B2
• Time in Patent Office: Days
• US Class Current: 711/113
• 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 solid-state storage as cache for high-capacity, non-volatile storage. The apparatus, system, and method are provided with a plurality of modules including a cache front-end module and a cache back-end module. The cache front-end module manages data transfers associated with a storage request. The data transfers between a requesting device and solid-state storage function as cache for one or more HCNV storage devices, and the data transfers may include one or more of data, metadata, and metadata indexes. The solid-state storage may include an array of non-volatile, solid-state data storage elements. The cache back-end module manages data transfers between the solid-state storage and the one or more HCNV storage devices.

Claims

1. An apparatus for managing the storage of data on one or more high capacity, non-volatile (“

HCNV”

) storage devices, the apparatus comprising;

a cache front-end module that manages data transfers associated with a storage request, the data transfers between a requesting device and solid-state storage functioning as cache for one or more HCNV storage devices, the data transfers comprising one or more of data, metadata, and metadata indexes, the solid-state storage comprising an array of non-volatile, solid-state data storage elements; and

a cache back-end module that manages data transfers between the solid-state storage and the one or more HCNV storage devices.

2. The apparatus of claim 1, wherein the cache front-end module and the cache back-end module are co-located with a solid-state storage controller that manages the solid-state storage.

3. The apparatus of claim 2, wherein the cache front-end module, the cache back-end module, and the solid-state storage controller operate autonomously from the requesting device.

4. The apparatus of claim 1, wherein the solid state controller further comprises an object storage controller module that services object requests from one or more requesting devices and manages objects of the object requests within the solid-state storage.

5. The apparatus of claim 1, further comprising an HCNV RAID module that stores data cached in the solid-state storage in two or more HCNV storage devices in redundant array of independent drives (“

RAID”

) consistent with a RAID level, wherein the data appears to a requesting device as a whole.

6. The apparatus of claim 1, wherein the solid-state storage and the one or more HCNV storage device comprise a hybrid storage device within a hybrid storage devices set that is configured as a RAID group, wherein a data segment cached in the solid-state storage and later stored on an HCNV device comprises one of N data segments of a stripe or a parity data segment of the stripe, wherein the hybrid storage device receives storage requests from one or more clients independent of data segments of a RAID stripe.

7. The apparatus of claim 6, wherein the hybrid storage device is a storage device of a shared, front-end distributed RAID group that receives two or more simultaneous storage requests from two or more clients.

8. The apparatus of claim 1, wherein the HCNV storage device is one of a hard disk drive (“

HDD”

), an optical drive, and a tape storage.

9. The apparatus of claim 1, wherein the solid-state storage and the one or more HCNV storage devices comprise a hybrid storage device and further comprising a standard device emulation module that provides access to the hybrid storage device by emulating a standard device attached to one or more requesting devices prior to loading the one or more requesting devices with code specific to the operation of the hybrid storage device, the standard device being supported by an industry standard BIOS.

10. The apparatus of claim 1, wherein the solid-state storage device may be partitioned into two or more regions, wherein one or more partitions may be used as solid-state storage independent of the solid-state storage functioning as cache for the HCNV storage devices.

11. The apparatus of claim 1, wherein one or more clients send cache control messages to the cache front-end module and the cache back-end module to manage a state of one or more of files or objects stored within the solid-state storage device and the one or more HCNV storage devices.

12. The apparatus of claim 11, wherein the cache control messages comprise one or more of:

a control message that causes the cache back-end module to pin a portion of an object or file in the solid-state storage;

a control message that causes the cache back-end module to unpin a portion of an object or file in the solid-state storage;

a control message that causes the cache back-end module to flush a portion of an object or file from the solid-state storage to the one or more HCVN storage devices;

a control message that causes the cache back-end module to preload a portion of an object or file to the solid-state storage from the one or more HCVN storage devices;

a control message that causes the cache back-end module to offload one or more portions of one or more objects or files from the solid-state storage to the one or more HCVN storage devices in order to free up a determined amount of storage space in the solid-state storage;

13. The apparatus of claim 11, wherein the cache control messages are communicated through metadata (“

cache control metadata”

) for the object or file.

14. The apparatus of claim 13, wherein the cache control metadata is persistent.

15. The apparatus of claim 13, wherein the cache control metadata is established through attributes set at a time of creation of the file or object.

16. The apparatus of claim 13, wherein the cache control metadata is obtained from a file or object management system.

17. The apparatus of claim 1, further comprising a volatile cache storage element and wherein the cache front-end module and the cache back-end module further comprise storing data in the volatile cache storage element and manage data stored in the solid-state storage and volatile cache storage element and wherein the back-end storage module further manages data transfers between the volatile cache storage element, the solid state storage, and the HCVN storage devices.

18. The apparatus of claim 17, wherein one or more of metadata and index metadata for objects and files stored in the HCVN storage devices is maintained within the solid-state storage device and the volatile cache storage element.

19. The apparatus of claim 1, wherein one or more of metadata and index metadata for objects and files stored in the HCVN storage devices is maintained within the solid-state storage device.

20. The apparatus of claim 1, wherein the solid-state storage and the one or more HCNV storage devices comprise a storage device such that the HCNV storage devices are hidden from view of a client connected to the storage device.

21. A system for managing the storage of data on one or more high capacity, non-volatile (“

HCNV”

) storage devices, the system comprising;

a solid-state storage comprising an array of non-volatile, solid-state data storage elements;

one or more HCNV storage devices; and

a storage controller comprising

a solid-state storage controller;

an HCNV storage device controller;

a cache front-end module that manages data transfers associated with a storage request, the data transfers between a requesting device and the solid-state storage functioning as cache for the one or more HCNV storage devices, the data transfers comprising one or more of data, metadata, and metadata indexes; and

a cache back-end module that manages data transfers between the solid-state storage and the one or more HCNV storage devices.

22. The system of claim 21, further comprising a network interface connected to the storage controller, the network interface facilitating data transfers between the requesting device and the solid-state storage controller through a computer network.

23. The system of claim 21, further comprising a server, wherein the server includes the solid-state storage, the one or more HCNV storage devices, and the storage controller.

24. The system of claim 21, wherein the one or more HCNV storage devices are connected to the storage controller through a storage area network (“

SAN”

).

25. A computer program product comprising a computer readable medium having computer usable program code executable to perform operations for managing the storage of data on one or more high capacity, non-volatile (“

HCNV”

) storage devices, the operations of the computer program product comprising;

managing data transfers associated with a storage request, the data transfers between a requesting device and solid-state storage functioning as c ache for one or more HCNV storage devices, the data transfers comprising one or more of data, metadata, and metadata indexes, the solid-state storage comprising an array of non-volatile, solid-state data storage elements; and

managing data transfers between the solid-state storage and the one or more HCNV storage devices.