Proactively correcting behavior that may affect I/O performance in a non-volatile semiconductor storage device

• US 9,684,460 B1
• Filed: 07/29/2016
• Issued: 06/20/2017
• Est. Priority Date: 09/15/2010
• Status: Active Grant

• Current Assignee: Pure Storage, Inc.
• Original Assignee: Pure Storage, Inc.
• Inventors: Colgrove, John, Hayes, John, Miller, Ethan, Wang, Feng, Harmer, Craig, Hong, Bo
• Primary Examiner(s): Gu, Shawn X
• Application Number:
  US15/224,281
• Time in Patent Office: 326 Days
• CPC Class Codes: G06F 12/0238 Memory management in non-volatile memory, e.g. resistive RAM or ferroelectric memory
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/08 in hierarchically structured memory systems, e.g. virtual memory systems
• CPC Class Codes: G06F 12/0802 Addressing of a memory level in which the access to the desired data or data block requires associative addressing means, e.g. caches
• CPC Class Codes: G06F 12/0891 using clearing, invalidating or resetting means
• CPC Class Codes: G06F 2212/60 Details of cache memory
• CPC Class Codes: G06F 3/06 Digital input from, or digital output to, record carriers , e.g. RAID, emulated record carriers or networked record carriers
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/0629 Configuration or reconfiguration of storage systems
• CPC Class Codes: G06F 3/0653 Monitoring storage devices or systems
• 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 3/0656 Data buffering arrangements
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0683 Plurality of storage devices
• CPC Class Codes: G06F 3/0688 Non-volatile semiconductor memory arrays
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A system and method for scheduling read and write operations among a plurality of solid-state storage devices. A computer system comprises client computers and data storage arrays coupled to one another via a network. A data storage array utilizes solid-state drives and Flash memory cells for data storage. A storage controller within a data storage array comprises an I/O scheduler. The data storage controller is configured to receive requests targeted to the data storage medium, said requests including a first type of operation and a second type of operation. The controller is further configured to schedule requests of the first type for immediate processing by said plurality of storage devices, and queue requests of the second type for later processing by the plurality of storage devices. Operations of the first type may correspond to operations with an expected relatively low latency, and operations of the second type may correspond to operations with an expected relatively high latency.

Claims

1. A method of proactively addressing conditions that affect input/output (′

I/O′

) performance in a non-volatile semiconductor storage system that includes a plurality of non-volatile semiconductor storage devices, the method comprising;

monitoring, for a non-volatile semiconductor storage devices, one or more non-volatile semiconductor device-related performance attributes;

determining, for the non-volatile semiconductor storage device in dependence upon the one or more non-volatile semiconductor device-related performance attributes, whether the non-volatile semiconductor storage device is exhibiting a behavior that may affect I/O performance, including determining whether the non-volatile semiconductor storage device is about to perform an internal cache flush; and

responsive to determining that the non-volatile semiconductor storage device is exhibiting the behavior that may affect I/O performance, scheduling a proactive operation associated with the behavior on the non-volatile semiconductor storage device.

2. The method of claim 1 wherein scheduling the proactive operation associated with the behavior on the non-volatile semiconductor storage device further comprises scheduling the internal cache flush.

3. The method of claim 1 wherein monitoring one or more non-volatile semiconductor device-related performance attributes further comprises determining an idle time for the non-volatile semiconductor storage device.

4. The method of claim 1 wherein the one or more non-volatile semiconductor device-related performance attributes include device-specific attributes.

5. The method of claim 1 wherein the one or more non-volatile semiconductor device-related performance attributes include I/O traffic-specific attributes.

6. The method of claim 1 wherein monitoring the one or more non-volatile semiconductor device-related performance attributes further comprises polling the non-volatile semiconductor storage device for the one or more non-volatile semiconductor device-related performance attributes.

7. The method of claim 1 wherein monitoring the one or more non-volatile semiconductor device-related performance attributes further comprises determining a number of pending write requests issued to the non-volatile semiconductor storage device.

8. The method of claim 1 wherein monitoring the one or more non-volatile semiconductor device-related performance attributes further comprises determining a pending amount of data to be written to the non-volatile semiconductor storage device.

9. The method of claim 1 wherein scheduling the proactive operation associated with the behavior on the non-volatile semiconductor storage device further comprises scheduling a reboot of the non-volatile semiconductor storage device.

10. The method of claim 1 wherein scheduling the proactive operation associated with the behavior on the non-volatile semiconductor storage device further comprises scheduling a reformatting of the non-volatile semiconductor storage device.

11. The method of claim 1 wherein scheduling the proactive operation associated with the behavior on the non-volatile semiconductor storage device further comprises scheduling a dummy read operation.

12. The method of claim 1 further comprising determining one or more device related attributes for the non-volatile semiconductor storage device.

13. A non-volatile semiconductor storage system that includes a plurality of non-volatile semiconductor storage devices, the non-volatile semiconductor storage system including a computer processor and a computer memory, the computer memory including computer program instructions that, when executed by the computer processor, cause the non-volatile semiconductor storage system to carry out the steps of:

monitoring, for a non-volatile semiconductor storage device, one or more non-volatile semiconductor device-related performance attributes;

determining, for the non-volatile semiconductor storage device in dependence upon the one or more non-volatile semiconductor device-related performance attributes, whether the non-volatile semiconductor storage device is exhibiting a behavior that may affect I/O performance, including determining whether the non-volatile semiconductor storage device is about to perform an internal cache flush; and

responsive to determining that the non-volatile semiconductor storage device is exhibiting the behavior that may affect I/O performance, scheduling a proactive operation associated with the behavior on the non-volatile semiconductor storage device.

14. The non-volatile semiconductor storage system of claim 13 wherein scheduling the proactive operation associated with the behavior on the non-volatile semiconductor storage device further comprises scheduling the internal cache flush.

15. The non-volatile semiconductor storage system of claim 13 wherein monitoring one or more non-volatile semiconductor device-related performance attributes further comprises determining an idle time for the non-volatile semiconductor storage device.

16. The non-volatile semiconductor storage system of claim 13 wherein the one or more non-volatile semiconductor device-related performance attributes include device-specific attributes.

17. The non-volatile semiconductor storage system of claim 13 wherein the one or more non-volatile semiconductor device-related performance attributes include I/O traffic-specific attributes.

18. The non-volatile semiconductor storage system of claim 13 wherein monitoring the one or more non-volatile semiconductor device-related performance attributes further comprises polling the non-volatile semiconductor storage device for the one or more non-volatile semiconductor device-related performance attributes.