Power aware power safe write buffer

• US 9,600,205 B1
• Filed: 09/22/2014
• Issued: 03/21/2017
• Est. Priority Date: 09/22/2014
• Status: Active Grant

• Current Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Original Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Inventors: Nowell, Shane G., Vinson, Wayne H., Fox, Travis D., Kastler, Danny J., Olds, Edwin Scott
• Primary Examiner(s): Gu, Shawn X
• Assistant Examiner(s): EDOUARD, JEAN C
• Application Number:
  US14/492,439
• Time in Patent Office: 911 Days
• US Class Current: 1/1
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 2212/281 Single cache
• CPC Class Codes: G06F 3/0625 Power saving in storage systems
• 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 3/0673 Single storage device
• CPC Class Codes: G06F 3/0676 Magnetic disk device
• CPC Class Codes: G06F 3/0683 Plurality of storage devices
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

Embodiments described herein relate to systems and methods for decreasing power consumption of a storage device. More specifically, embodiments disclosed herein are directed to reducing power consumption of a data storage device by enabling a command buffer associated with the data storage device to store received commands without executing the commands until a predetermined number of commands have been stored in the buffer.

Claims

1. A method for writing data to a data storage system, comprising:

receiving, at a storage device, a plurality of write commands from a host device;

storing, at the storage device, the plurality of write commands in an internal command queue unique from a host command queue;

determining whether a depth of the internal command queue exceeds a predetermined command queue depth, the predetermined command queue depth based on an average amount of power consumed by the storage device when executing write commands;

upon determining that the depth of the internal command queue exceeds the predetermined command queue depth;

performing one or more write commands in the internal command queue, wherein each performed write command writes data to a primary non-volatile memory of the data storage system and causes the depth of the internal command queue to decrease and wherein the one or more write commands are performed until the depth of the internal command queue reaches a minimum threshold; and

upon determining that the depth of the internal command queue does not exceed the predetermined command queue depth;

causing the storage device to not perform a write.

2. The method of claim 1, wherein the storage device comprises a power safe write buffer.

3. The method of claim 2, further comprising, upon determining that the power safe write buffer contains an amount of data greater than a threshold amount of data, performing one or more write commands in the internal command queue.

4. The method of claim 2, wherein the power safe write buffer comprises a non-volatile memory device.

5. The method of claim 2, wherein the power safe write buffer is a volatile state memory device protected by a non-volatile memory device.

6. The method of claim 1, further comprising ordering the one or more write commands using rotational positional ordering.

7. The method of claim 1, wherein the plurality of write commands are random write commands.

8. The method of claim 1, further comprising, in response to receiving the plurality of write commands, communicating to the host device that the plurality of write commands have been written to the storage device.

9. The method of claim 1, wherein the depth of the internal command queue is different from a depth of an internal write command queue and wherein the depth of the internal write command queue of the storage device is independent from a depth of a write command queue of the host device.

10. The method of claim 1, wherein performing one or more write commands in the internal command queue comprises slowing a seeking motion of an actuator of the storage device.

11. The method of claim 1, wherein performing one or more write commands in the internal command queue comprises using an elevator sorting method to select the write commands in the internal command queue for execution.

12. The method of claim 1, wherein performing one or more write commands in the internal command queue comprises spinning a disk of the storage device at a lower spin rate than when the rate of write commands received from the host device is above the threshold.

13. The method of claim 1, wherein the storage device performs write commands associated with pushing out data from a media based cache to a primary data storage in addition to the write commands received from the host device.

14. A non-transitory computer-readable storage medium encoding computer executable instructions which, when executed by a processor, performs a method for writing data to a data storage system, the method comprising:

receiving, at a storage device, a plurality of write commands from a host device;

storing, at the storage device, the plurality of write commands in an internal command queue unique from a host command queue;

determining whether a depth of the internal command queue exceeds a predetermined command queue depth, the predetermined command queue depth based, at least in part, on an average amount of power consumed by the storage device when executing write commands;

upon determining that the depth of the internal command queue exceeds the predetermined command queue depth;

performing one or more write commands in the internal command queue, wherein each performed write command writes data to a primary non-volatile memory of the data storage system and causes the depth of the internal command queue to decrease and wherein the one or more write commands are performed until the depth of the internal command queue reaches a minimum threshold; and

upon determining that the depth of the internal command queue does not exceed the predetermined command queue depth;

causing the storage device to not perform a write.

15. The non-transitory computer-readable storage medium of claim 14, further comprising instructions for ordering the one or more write commands using rotational positional ordering the one or more write commands using rotational positional ordering.

16. A data storage device, comprising:

data storage memory; and

a controller configured to;

receive a plurality of write commands from a host device;

store the plurality of write commands in an internal command queue;

perform one or more write commands in the internal command queue at a first rate;

determine whether a depth of the internal command queue exceeds a predetermined command queue depth that is based on an average amount of power consumed by the data storage device when executing write commands stored in the internal command queue; and

upon determining that the depth of the internal command queue exceeds the predetermined command queue depth;

perform one or more write commands in the internal command queue at a second rate that is different than the first rate, wherein each performed write command at the second rate causes the depth of the internal command queue to decrease and wherein the one or more write commands are performed at the second rate until the depth of the internal command queue reaches a minimum threshold.

17. The data storage device of claim 16, wherein the storage device comprises a power safe write buffer.

18. The data storage device of claim 17, further comprising, upon determining that the power safe write buffer contains an amount of data greater than a threshold amount of data, performing one or more write commands in the internal command queue at the second rate.

19. The data storage device of claim 17, wherein the power safe write buffer comprises a non-volatile memory device.

20. The data storage device of claim 17, wherein the power safe write buffer is a volatile state memory device protected by a non-volatile memory device.