EFFICIENT CONNECTION MANAGEMENT IN A SAS TARGET

• US 20120265903A1
• Filed: 04/05/2012
• Published: 10/18/2012
• Est. Priority Date: 04/17/2011
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Anobit Technologies, Ltd. (Apple Inc.)
• Inventors: Peled, Arie
• Granted Patent: US 8,719,457 B2
• Time in Patent Office: Days
• US Class Current: 710/5
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/0655 Vertical data movement, i.e. input-output transfer; data movement between one or more hosts and one or more storage devices
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0661 Format or protocol conversion arrangements
• CPC Class Codes: G06F 3/068 Hybrid storage device
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: G11B 5/09 Digital recording

Abstract

A method includes pre-configuring a hardware-implemented front-end of a storage device with multiple contexts of respective connections conducted between one or more hosts and the storage device. Storage commands, which are received in the storage device and are associated with the connections having the pre-configured contexts, are executed in a memory of the storage device using the hardware-implemented front-end. Upon identifying a storage command associated with a context that is not pre-configured in the hardware-implemented front-end, software of the storage device is triggered to configure the context in the hardware-implemented front-end, and the storage command is then executed using the hardware-implemented front-end in accordance with the context configured by the software.

Claims

1. A method for data storage, comprising:

pre-configuring a hardware-implemented front-end of a storage device with multiple contexts of respective connections conducted between one or more hosts and the storage device;

executing in a memory of the storage device, using the hardware-implemented front-end, storage commands that are received in the storage device and are associated with the connections having the pre-configured contexts; and

upon identifying a storage command associated with a context that is not pre-configured in the hardware-implemented front-end, triggering software of the storage device to configure the context in the hardware-implemented front-end, and then executing the storage command using the hardware-implemented front-end in accordance with the context configured by the software.

2. The method according to claim 1, wherein the storage commands are received in accordance with a Serial Attached Storage (SAS) storage protocol.

3. The method according to claim 1, wherein the storage device comprises a Solid State Disk (SSD).

4. The method according to claim 1, wherein triggering the software comprises issuing an interrupt to a Central Processing Unit (CPU) that runs the software.

5. The method according to claim 1, wherein triggering the software comprises causing the software to replace a previously-configured context in the hardware-implemented front-end with the context associated with the identified storage command.

6. The method according to claim 1, wherein executing the storage commands comprises carrying out the storage commands without involvement of a Central Processing Unit (CPU) that runs the software.

7. A data storage apparatus, comprising:

a Central Processing Unit (CPU); and

a hardware-implemented front-end, which is pre-configured with multiple contexts of respective connections conducted between one or more hosts and the apparatus, and which is arranged to execute in a memory of the apparatus storage commands that are received in the apparatus and are associated with the connections having the pre-configured contexts, and, upon identifying a storage command associated with a context that is not pre-configured in the hardware-implemented front-end, to trigger software running in the CPU to configure the context in the hardware-implemented front-end, and then to execute the storage command in accordance with the context configured by the software.

8. The apparatus according to claim 7, wherein the storage commands are received in accordance with a Serial Attached Storage (SAS) storage protocol.

9. The apparatus according to claim 7, wherein the CPU, the hardware-implemented front-end and the memory are comprised in a Solid State Disk (SSD).

10. The apparatus according to claim 7, wherein the hardware-implemented front-end is arranged to trigger the software by issuing an interrupt to the CPU.

11. The apparatus according to claim 7, wherein the CPU is arranged to replace a previously-configured context in the hardware-implemented front-end with the context associated with the identified storage command.

12. The apparatus according to claim 7, wherein the hardware-implemented front-end is arranged to execute the storage commands without involvement of the CPU.

13. A method for data storage, comprising:

in a hardware-implemented front-end of a storage device, opening at least one connection, executing in a memory of the storage device storage commands associated with at least one connection, closing the at least one connection after executing the storage commands, and caching one or more contexts of respective one or more connections that were most recently closed;

receiving a storage command associated with a given connection that is not currently open;

checking the given connection against the cached contexts; and

upon identifying that the given connection is one of the one or more connections that were most recently closed, re-opening the given connection using one of the cached contexts and executing the storage command using the hardware-implemented front-end in accordance with the one of the contexts.

14. The method according to claim 13, wherein the storage commands are received in accordance with a Serial Attached Storage (SAS) storage protocol.

15. The method according to claim 13, wherein the storage device comprises a Solid State Disk (SSD).

16. The method according to claim 13, wherein closing the at least one connection comprises closing each connection following a predefined inactivity period on the connection.

17. The method according to claim 13, wherein executing the storage commands comprises carrying out the storage commands without involvement of a Central Processing Unit (CPU) of the storage device.

18. A data storage apparatus, comprising:

an interface, which is arranged to communicate with one or more hosts; and

a hardware-implemented front-end, which is arranged to open at least one connection, to execute in a memory of the apparatus storage commands associated with the at least one connection, to close the at least one connection after executing the storage commands, to cache one or more contexts of respective one or more connections that were most recently closed, to receive a storage command associated with a given connection that is not currently open, to check the given connection against the cached contexts, and, upon identifying that the given connection is one of the one or more connections that were most recently closed, to re-open the given connection using one of the cached contexts and to execute the storage command in accordance with the one of the cached contexts.

19. The apparatus according to claim 18, wherein the storage commands are received in accordance with a Serial Attached Storage (SAS) storage protocol.

20. The apparatus according to claim 18, wherein the interface, the hardware-implemented front-end and the memory are comprised in a Solid State Disk (SSD).

21. The apparatus according to claim 18, wherein the hardware-implemented front-end is arranged to close each connection following a predefined inactivity period on the connection.

22. The apparatus according to claim 18, wherein the hardware-implemented front-end is arranged to execute the storage commands without involvement of a Central Processing Unit (CPU) of the apparatus.