Reducing flash memory write amplification and latency

• US 9,183,142 B2
• Filed: 05/03/2013
• Issued: 11/10/2015
• Est. Priority Date: 03/15/2013
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Shivashankaraiah, Vinay Bangalore
• Primary Examiner(s): PEUGH, BRIAN R
• Application Number:
  US13/886,325
• Publication Number:
  US 20140281143A1
• Time in Patent Office: 921 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 12/0246 in block erasable memory, e.g. flash memory
• CPC Class Codes: G06F 12/0253 Garbage collection, i.e. reclamation of unreferenced memory
• CPC Class Codes: G06F 2212/7205 Cleaning, compaction, garbage collection, erase control
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

Data is distributed to solid-state disks (SSDs) using the RAID-0 technique. Based on a utilization of a first region of a first one of the SSDs, the first region is selected for garbage collection. Valid data from the first region is copied to an active region of the first one of the SSDs as part of a process of garbage collection. While the process of garbage collection is being performed, data is distributed to a subset of the SSDs using the RAID-0 technique where the subset of the SSDs does not include the first one of the plurality of nonvolatile solid-state memories selected for garbage collection.

Claims

1. A method of storing data to a nonvolatile solid-state memory, comprising:

distributing data from a host to a plurality of nonvolatile solid-state memories using a RAID-0 technique;

based on a utilization of a first region of a first one of the plurality of nonvolatile solid-state memories, selecting the first region of the first one of the plurality of nonvolatile solid-state memories for garbage collection;

copying valid data from a region of a nonvolatile random access memory to at least the first region of the first one of the plurality of nonvolatile solid-state memories as part of a process of garbage collection; and

while the process of garbage collection is being performed, distributing the data from the host to a subset of the plurality of nonvolatile solid-state memories using the RAID-0 technique, the subset of the plurality of nonvolatile solid-state memories not including the first one of the plurality of nonvolatile solid-state memories selected for garbage collection.

2. The method of claim 1, further comprising:

after the process of garbage collection is complete on the first region of the first one of the plurality of nonvolatile solid-state memories, distributing the data from the host to the complete set of the plurality of nonvolatile solid-state memories using the RAID-0 technique.

3. The method of claim 1, further comprising:

maintaining a first set of flags to indicate which of the plurality of nonvolatile solid-state memories is undergoing the process of garbage collection.

4. The method of claim 3, further comprising:

maintaining a second set of flags to indicate which of the plurality of nonvolatile solid-state memories being used for garbage collection information on a respective active region of the plurality of nonvolatile solid-state memories.

5. The method of claim 4, further comprising:

maintaining a third set of flags associated with a plurality of logical block addresses that indicate when metadata associated with each of the plurality of logical block addresses has not been written to the plurality of nonvolatile solid-state memories.

6. The method of claim 3, further comprising:

after the process of garbage collection is complete on the first region of the first one of the plurality of nonvolatile solid-state memories, distributing the data from the host to the complete set of the plurality of nonvolatile solid-state memories using the RAID-0 technique.

7. A nonvolatile solid-state memory storage system, comprising:

a plurality of nonvolatile solid-state memories; and

a nonvolatile solid-state memory driver configured to distribute data from a host to the plurality of nonvolatile solid-state memories using a RAID-0 technique and configured to, based on a utilization of a first region of a first one of the plurality of nonvolatile solid-state memories, select the first region of the first one of the plurality of nonvolatile solid-state memories for garbage collection, and configured to copy valid data from a region of a nonvolatile random access memory to at least the first region of the first one of the plurality of nonvolatile solid-state memories as part of a process of garbage collection, and configured to, while the process of garbage collection is being performed, distribute the data from the host to a subset of the plurality of nonvolatile solid-state memories using the RAID-0 technique, the subset of the plurality of nonvolatile solid-state memories not including the first one of the plurality of nonvolatile solid-state memories selected for garbage collection.

8. The storage system of claim 7, wherein the nonvolatile solid-state memory driver is further configured to:

after the process of garbage collection is complete on the first region of the first one of the plurality of nonvolatile solid-state memories, distribute the data from the host to the complete set of the plurality of nonvolatile solid-state memories using the RAID-0 technique.

9. The storage system of claim 7, wherein the nonvolatile solid-state memory driver is further configured to:

maintain a first set of flags to indicate which of the plurality of nonvolatile solid-state memories is undergoing the process of garbage collection.

10. The storage system of claim 9, wherein the nonvolatile solid-state memory driver is further configured to:

maintain a second set of flags to indicate which of the plurality of nonvolatile solid-state memories being used for garbage collection information on a respective active region of the plurality of nonvolatile solid-state memories.

11. The storage system of claim 10, wherein the nonvolatile solid-state memory driver is further configured to:

maintain a third set of flags associated with a plurality of logical block addresses that indicate when metadata associated with each of the plurality of logical block addresses has not been written to the plurality of nonvolatile solid-state memories.

12. The storage system of claim 9, wherein the nonvolatile solid-state memory driver is further configured to:

after the process of garbage collection is complete on the first region of the first one of the plurality of nonvolatile solid-state memories, distribute the data from the host to the complete set of the plurality of nonvolatile solid-state memories using the RAID-0 technique.

13. The storage system of claim 7, wherein each of the plurality of nonvolatile solid-state memories are included in solid-state disks having a respective controller that is responsive to instructions received from the nonvolatile solid-state memory driver.

14. The storage system of claim 7, wherein the plurality of nonvolatile solid-state memories and the nonvolatile random access memory are included in a host bus adapter.

15. A non-transitory computer readable medium having instructions stored thereon for storing data to a nonvolatile solid-state memory that, when executed by a computer, at least instruct the computer to:

distribute data from a host to a plurality of nonvolatile solid-state memories using a RAID-0 technique;

based on a utilization of a first region of a first one of the plurality of nonvolatile solid-state memories, select the first region of the first one of the plurality of nonvolatile solid-state memories for garbage collection;

copy valid data from the first region of the first one of the plurality of nonvolatile solid-state memories to an active region of the first one of the plurality of nonvolatile solid-state memories as part of a process of garbage collection; and

while the process of garbage collection is being performed, distribute the data from the host to a subset of the plurality of nonvolatile solid-state memories using the RAID-0 technique, the subset of the plurality of nonvolatile solid-state memories not including the first one of the plurality of nonvolatile solid-state memories selected for garbage collection.

16. The medium of claim 15, wherein the computer is further instructed to:

after the process of garbage collection is complete on the first region of the first one of the plurality of nonvolatile solid-state memories, distribute the data from the host to the complete set of the plurality of nonvolatile solid-state memories using the RAID-0 technique.

17. The medium of claim 15, wherein the computer is further instructed to:

maintain a first set of flags to indicate which of the plurality of nonvolatile solid-state memories is undergoing the process of garbage collection.

18. The medium of claim 17, wherein the computer is further instructed to:

maintain a second set of flags to indicate which of the plurality of nonvolatile solid-state memories being used for garbage collection information on a respective active region of the plurality of nonvolatile solid-state memories.

19. The medium of claim 18, wherein the computer is further instructed to:

maintaining a third set of flags associated with a plurality of logical block addresses that indicate when metadata associated with each of the plurality of logical block addresses has not been written to the plurality of nonvolatile solid-state memories.

20. The medium of claim 17, wherein the computer is further instructed to:

after the process of garbage collection is complete on the first region of the first one of the plurality of nonvolatile solid-state memories, distribute the data from the host to the complete set of the plurality of nonvolatile solid-state memories using the RAID-0 technique.