Adaptive prefecth for predicted write requests

Patent metadata

Field	Value
Publication number	US-9298633-B1
Application number	US-201314030511-A
Country	US
Kind code	B1
Filing date	Sep 18, 2013
Priority date	Sep 18, 2013
Publication date	Mar 29, 2016
Grant date	Mar 29, 2016

Abstract

Implementations are provided herein relating to adaptive prefetch for predicted write requests. A set of I/O requests associated with a set of storage devices and a set of cache memory can be monitored. Through the application of a prefetch algorithm to the set of monitored I/O requests, future write requests can be predicted. Data blocks corresponding to the predicted future write requests can be read in parallel with other disk I/O and preloaded into cache for access by, for example, data protection processes. In this sense the efficiency of data protection processes can be enhanced by reducing sequential disk I/O requests.

First claim

What is claimed is:

1. A system comprising:
a memory that has stored thereon computer executable components; and
a processor that executes the following computer executable components stored in the memory:
a monitoring component that monitors a set of input/output (“I/O”) requests associated with a set of cache memory and a set of storage devices;
a predictive prefetch component that predicts a future write request based on the set of I/O requests and a prefetch algorithm, wherein the future write request is associated with a first set of data blocks within the set of storage devices; and
an advanced reading component that based on a prefetch status associated with the first set of data blocks, in response to an I/O request associated with a second set of data blocks within the set of storage devices, in parallel, performs the I/O request and writes the first set of data blocks to the set of cache memory from the set of storage devices.

2. The system of claim 1 , wherein the monitoring component dynamically monitors the set of I/O requests.

3. The system of claim 1 , wherein the predictive prefetch component dynamically predicts the future write request.

4. The system of claim 1 , wherein the set of I/O requests includes associated metadata.

5. The system of claim 4 , wherein metadata associated with I/O requests in the set of I/O requests include at least one of a storage device location, a data block location, a file system location, or a timestamp.

6. The system of claim 1 , further comprising:
a disc storage component that reads the first set of data blocks from the set of cache memory and writes the first set of data blocks to a second storage device separate from the set of storage devices.

7. The system of claim 1 , further comprising:
a snapshot storage component that in response to the advanced reading component writing the first set of data blocks to the set of cache memory, sends the first set of data blocks to a snapshot storage system.

8. The system of claim 1 , further comprising:
an optimization component that determines the prefetch status based on metadata associated with the first set of data blocks.

9. The system of claim 7 wherein the snapshot storage system is separate from the cache memory and the set of storage devices.

10. A method comprising:
monitoring a set of I/O requests associated with a set of cache memory and a set of storage devices;
predicting a future write request based on the set of I/O requests and a prefetch algorithm wherein the future write request is associated with a first set of data blocks within the set of storage devices;
in response to receiving an I/O request associated with a second set of data blocks, based on a prefetch status associated with the first set of data blocks, performing the I/O request and writing the first set of data blocks to the set of cache memory, wherein the performing the I/O request and the writing the first set of data blocks occur in parallel.

11. The method of claim 10 , wherein the monitoring the set of I/O requests is dynamic.

12. The method of claim 11 , wherein the predicting the future write request is dynamic.

13. The method of claim 10 , wherein the set of I/O requests includes associated metadata.

14. The method of claim 13 , wherein metadata associated with I/O requests in the set of I/O requests includes at least one of a storage device location, a data block location, a file system location, or a timestamp.

15. The method of claim 10 , further comprising:
reading the first set of data blocks from the set of cache memory; and
writing the first set of data blocks to a storage device in the set of storage devices.

16. The method of claim 10 , further comprising:
in response to the writing the first set of data blocks to the set of cache memory, sending the first set of data blocks to a snapshot storage system.

17. The method of claim 10 , further comprising:
in response to predicting the future write request, determining the prefetch status based on metadata associated with the first set of data blocks.

18. A non-transitory computer readable medium with program instructions stored thereon to perform the following acts:
monitoring a set of I/O requests associated with a set of cache memory and a set of storage devices;
predicting a future write request based on the set of I/O requests and a prefetch algorithm wherein the future write request is associated with a first set of data blocks within the set of storage devices;
in response to receiving an I/O request associated with a second set of data blocks, based on a prefetch status associated with the first set of data blocks, performing the I/O request and writing the first set of data blocks to the set of cache memory, wherein the performing the I/O request and the writing the first set of data blocks occur in parallel.

19. The non-transitory computer readable medium of claim 18 , further comprising:
in response to the writing the first set of data blocks to cache memory, sending the first set of data blocks to a snapshot storage system.

20. The non-transitory computer readable medium of claim 18 , further comprising:
in response to predicting the future write request, determining the prefetch status based on metadata associated with the first set of data blocks.

Assignees

• Emc Corp

Inventors

• Zhao Junping
• Basov Ivan

Classifications

• G06F12/0862 Primary

  with prefetch · CPC title

• G06F11/1446

  Point-in-time backing up or restoration of persistent data · CPC title

• G06F2212/1032

  Reliability improvement, data loss prevention, degraded operation etc · CPC title

• G06F2212/1016

  Performance improvement · CPC title

• G06F2201/84

  Using snapshots, i.e. a logical point-in-time copy of the data · CPC title