System for dynamically adaptive caching

Patent metadata

Field	Value
Publication number	US-9158695-B2
Application number	US-201213566204-A
Country	US
Kind code	B2
Filing date	Aug 3, 2012
Priority date	Aug 9, 2011
Publication date	Oct 13, 2015
Grant date	Oct 13, 2015

Abstract

The present disclosure is directed to a system for dynamically adaptive caching. The system includes a storage device having a physical capacity for storing data received from a host. The system may also include a control module for receiving data from the host and compressing the data to a compressed data size. Alternatively, the data may also be compressed by the storage device. The control module may be configured for determining an amount of available space on the storage device and also determining a reclaimed space, the reclaimed space being according to a difference between the size of the data received from the host and the compressed data size. The system may also include an interface module for presenting a logical capacity to the host. The logical capacity has a variable size and may include at least a portion of the reclaimed space.

First claim

What is claimed is:

1. A method for managing a dynamically adaptive cache including a storage device, comprising the steps of:
receiving data from a host;
compressing the received data to a compressed data;
storing the compressed data;
determining an amount of available space on the storage device;
increasing a logical capacity presented to the host by an amount according to at least a portion of a difference between a size of the received data and a size of the compressed data when the amount of available space on the storage device is greater than a configuration threshold.

2. The method of claim 1 , further comprising the step of:
releasing space when the amount of available space is less than a reserve amount.

3. The method of claim 2 , further comprising the step of:
signaling when the amount of available space is less than the reserve amount.

4. The method of claim 1 , wherein the determining an amount of available space includes:
signaling when the amount of available space is greater than the configuration threshold;
sending a query to determine the amount of available space.

5. The method of claim 1 , wherein each step of the method is performed each time data is received from the host.

6. The method of claim 1 , wherein the step of compressing the received data to a compressed data includes compressing the data using lossless algorithms.

7. A system for dynamically adaptive caching, comprising:
a storage device, the storage device having a physical capacity for storing data received from a host;
a compression module, the compression module for compressing the data received from the host to a compressed data size;
a control module, the control module configured for receiving data from the host, the control module further configured for determining an amount of available space on the storage device, the control module further configured for determining a reclaimed space, the reclaimed space according to a difference between the size of the data received from the host and the compressed data size;
an interface module, the interface module configured for presenting a logical capacity to the host, the logical capacity having a variable size; the logical capacity including at least a portion of the reclaimed space.

8. The system of claim 7 , wherein the control module is further configured for releasing space on the storage device when the amount of available space on the storage device is less than a reserve amount.

9. The system of claim 7 , wherein the storage device is a solid-state drive.

10. The system of claim 7 , wherein a fixed minimum logical capacity is presented to the host.

11. A method comprising:
receiving, by a storage device over a storage interface, a plurality of data portions;
reducing each of the data portions to form respective reduced data portions, at least some of the data portions having a larger size than the respective reduced data portions;
storing the data portions as the reduced data portions in a data memory of the storage device; and
determining a logical capacity of the data memory according to a utilization of the data memory, wherein the logical capacity of the data memory varies according to the reducing;
wherein the logical capacity increases as a difference between a total size of the data portions and a total size of the reduced data portions increases.

12. The method of claim 11 , wherein the logical capacity corresponds to a number of the data portions that the data memory is able to store.

13. The method of claim 11 , further comprising:
in response to the utilization exceeding a specified threshold, removing one or more of the reduced data portions from the data memory.

14. The method of claim 13 , wherein the removing comprises invalidating one or more entries of a tag memory of the storage device.

15. The method of claim 13 , wherein the specified threshold maintains a write amplification of the storage device below a specified value.

16. The method of claim 11 , wherein the logical capacity decreases as a difference between a total size of the data portions and a total size of the reduced data portions decreases.

17. The method of claim 11 , wherein the storage interface is one of a SATA interface, a SAS interface, and a PCIe interface.

18. The method of claim 11 , wherein the data memory is non-volatile.

19. The method of claim 11 , wherein the reducing comprises compressing.

20. The method of claim 11 , further comprising:
in response to a request to the storage device for a particular one of the data portions, reading the respective reduced data portion from the data memory, reversing the reducing of the respective reduced data portion to restore the particular data portion, and returning the particular data portion to the host.

Assignees

• Simionescu Horia
• Ish Mark
• Bert Luca
• Quinn Robert
• Cohen Earl T
• Canepa Timothy
• Seagate Technology Llc

Inventors

• Simionescu Horia
• Ish Mark
• Bert Luca
• Quinn Robert
• Cohen Earl T
• Canepa Timothy

Classifications

• G06F2212/401

  Compressed data · CPC title

• G06F12/0871 Primary

  Allocation or management of cache space · CPC title