Storage system with front-end controller

• US 8,601,211 B2
• Filed: 06/04/2012
• Issued: 12/03/2013
• 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: Flynn, David, Strasser, John, Thatcher, Jonathan, Zappe, Michael
• Primary Examiner(s): DUDEK JR, EDWARD J
• Application Number:
  US13/488,301
• Publication Number:
  US 20130067294A1
• Time in Patent Office: 547 Days
• Field of Search: 711/114, 711/E12.001, 710/8, 710/22
• US Class Current: 711/114
• 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

Embodiments are disclosure relating to a front-end controller in a storage system. In one embodiment, a storage request is received at a storage device in a group of storage devices. The storage request identifies one or more data segments of a data stripe pattern assigned to the storage device by a front-end controller of the group. In such an embodiment, the storage device communicates the identified data segments with a storage client independently of the front-end controller. In some embodiments, the storage system includes a front-end, distributed redundant array of independent drives (RAID). In one such embodiment, the storage devices independently receive storage requests from a client over a network, and one or more of the storage devices are designated as parity-mirror storage devices for a stripe.

Claims

1. A method, comprising:

receiving a storage request at a storage device in a group of storage devices, the storage request identifying one or more data segments of a data stripe pattern assigned to the storage device by a front-end controller of the group; and

the storage device communicating the identified data segments with a storage client independently of the front-end controller.

2. The method of claim 1, wherein the storage device communicates data directly with the storage client by way of one of a bus, direct memory access, remote direct memory access, network broadcast, network multicast, network anycast, and network unicast.

3. The method of claim 1, wherein the identified data segments comprise parity data of the data stripe pattern.

4. The method of claim 1, wherein the group of storage devices comprises a redundant array of independent disks (RAID) group, the method further comprising:

maintaining indicators of the storage devices in the RAID group on the storage device; and

reconstructing the RAID group using the indicators of the storage device.

5. The method of claim 1, further comprising:

receiving a second, different storage request at the storage device pertaining to a client storage request that is independent of the group of storage devices; and

storing data of the second storage request on the storage device with the identified data segments.

6. The method of claim 1, further comprising:

receiving a second storage request at the storage device referencing a second group of storage devices comprising a different plurality of storage devices, wherein the second storage request identifies one or more second data segments of a second data stripe pattern assigned to the storage device by the front-end controller; and

the storage device transferring the second identified data segments with a storage client independently of the front-end controller.

7. The method of claim 1, further comprising:

storing the identified data segments sequentially by order of processing on a solid-state storage media of the storage device;

marking storage divisions of the solid-state storage media with respective sequence indicators; and

reconstructing an index of data stored on the storage device based on the sequence indicators.

8. The method of claim 1, wherein the storage device comprises a plurality of solid-state storage elements, each solid-state storage element comprising a plurality of storage divisions, the method further comprising storing the identified data segments on two or more of the solid-state storage elements in parallel.

9. The method of claim 1, further comprising:

including data of the identified data segments in an error-correcting code (ECC) block that comprises an error-correcting code configured to correct an error in the ECC block;

storing a first portion of the ECC block on a first one of a plurality of solid-state storage elements; and

storing a second portion of the ECC block on a second one of the plurality of solid-state storage elements.

10. A storage device, comprising:

a storage request receiver configured to receive a storage request identifying one or more data segments of a data stripe calculated by a front-end controller of a group of storage devices; and

a storage controller configured to communicate the identified data segments with a storage client without communicating the identified data segments through the front-end controller.

11. The storage device of claim 10, wherein the storage device is configured to communicate data directly with the storage client by way of one of a bus, direct memory access, remote direct memory access, network broadcast, network multicast, network anycast, and network unicast.

12. The storage device of claim 10, wherein the identified data segments comprise parity data of the data stripe pattern.

13. The storage device of claim 10, wherein the group of storage devices comprises a redundant array of independent disks (RAID) group, and wherein the storage device is configured to maintain indicators of storage devices in the RAID group and is configured to reconstruct the RAID group using the indicators.

14. The storage device of claim 10, wherein the storage device is configured to store the identified data segments on a non-volatile storage media with data that does not pertain to the group of storage devices.

15. The storage device of claim 10, wherein the storage device is configured to mark storage divisions of a non-volatile storage media of the storage device with respective sequence indicators to indicate an order of storage operations performed on the storage device.

16. The storage device of claim 10, further comprising:

a plurality of solid-state storage elements, each solid-state storage element comprising a plurality of storage divisions; and

wherein the storage device is configured to store the identified data segments on two or more of the solid-state storage elements in parallel.

17. The storage device of claim 10, wherein the storage device is configured to generate an error-correcting code (ECC) block comprising data of the identified data segments and an error-correcting code;

and

wherein the storage device is configured to store a first portion of the ECC block on a first one of a plurality of solid-state storage elements and a second portion of the ECC block on a second one of the plurality of solid-state storage elements.

18. A storage system, comprising:

a front-end controller; and

a plurality of storage devices, each storage device comprising;

a storage controller configured to service a storage request identifying one or more data segments of a data stripe pattern that are assigned to the storage device by the front-end controller, and wherein the storage controller is configured to service the storage request by transmitting the identified one or more data segments to a storage client via one or more network paths that do not include the front-end controller.

19. The storage system of claim 18, wherein the front-end controller is configured to operate on one of the plurality of storage devices.

20. The storage system of claim 18, wherein each of the plurality of storage devices is configured to communicate data directly with the storage client in response to a storage request from the front-end controller.