System and method for accelerating anchor point detection

• US 9,069,787 B2
• Filed: 06/20/2014
• Issued: 06/30/2015
• Est. Priority Date: 05/31/2007
• Status: Expired due to Fees

• Current Assignee: NetApp, Inc.
• Original Assignee: NetApp, Inc.
• Inventors: Miller, Steven C., Stager, Roger
• Primary Examiner(s): Boccio, Vincent F
• Application Number:
  US14/310,286
• Publication Number:
  US 20140304241A1
• Time in Patent Office: 375 Days
• Field of Search: 707/662, 707/664, 707/692
• US Class Current: 1/1
• CPC Class Codes: G06F 16/1748 De-duplication implemented within the file system, e.g. based on file segments de-duplication techniques in storage systems for the management of data blocks G06F3/0641
• CPC Class Codes: H03M 7/3084 using adaptive string matching, e.g. the Lempel-Ziv method

Abstract

A sampling based technique for eliminating duplicate data (de-duplication) stored on storage resources, is provided. According to the invention, when a new data set, e.g., a backup data stream, is received by a server, e.g., a storage system or virtual tape library (VTL) system implementing the invention, one or more anchors are identified within the new data set. The anchors are identified using a novel anchor detection circuitry in accordance with an illustrative embodiment of the present invention. Upon receipt of the new data set by, for example, a network adapter of a VTL system, the data set is transferred using direct memory access (DMA) operations to a memory associated with an anchor detection hardware card that is operatively interconnected with the storage system. The anchor detection hardware card may be implemented as, for example, a FPGA is to quickly identify anchors within the data set. As the anchor detection process is performed using a hardware assist, the load on a main processor of the system is reduced, thereby enabling line speed de-duplication.

Claims

1. A method, comprising:

receiving a data set at a storage system;

in response to receiving the data set, detecting one or more anchor locations in the data set by an anchor detection circuitry of the storage system, wherein the anchor detection circuitry is dedicated for detecting the one or more anchor locations;

transferring each anchor location to a data de-duplication module executed by a processor of the storage system;

examining, by the de-duplication module executed by the processor, bits preceding the anchor location utilizing a first delta value and the bits following the anchor location utilizing a second delta value to identify duplicate data; and

in response to identifying the duplicate data, removing the duplicate data from the data set prior to storing the data set on a storage device operatively connected to the storage system.

2. The method of claim 1 wherein the anchor detection circuitry comprises a programmable logic device.

3. The method of claim 2 wherein the programmable logic device comprises a field programmable gate array.

4. The method of claim 1 further comprising adding the anchor location to a database.

5. A method, comprising:

detecting one or more anchor locations of a data set by an anchor detection circuitry of a storage system, wherein the anchor detection circuitry is a hardware device dedicated for detecting the one or more anchor locations;

transferring each anchor location to a de-duplication module executed by a processor of the storage system, wherein the anchor detection circuitry and the processor are separate hardware devices;

determining if the anchor location is located in a database;

if the anchor location is located in the database, performing data de-duplication for the data by examining a region surrounding the anchor location utilizing a first delta value identifying a number of consecutive bits before the anchor location and a second delta value identifying a number of consecutive bits after the anchor location to identify duplicate data; and

in response to identifying the duplicate data, removing the duplicate data from the data set prior to storing the data set on a storage device operatively connected to the storage system.

6. The method of claim 5 wherein the data set comprises a tape backup data set.

7. The method of claim 5 further comprising receiving the data set at a network adapter of the storage system.

8. The method of claim 5 further comprising performing a direct memory access operation to transfer the data set to the anchor detection circuitry in response to receiving the data set from a client.

9. The method of claim 5 wherein detecting the one or more anchor locations further comprises performing a rolling hash on the data set.

10. A system, comprising:

anchor detection hardware of a storage system that is configured to receive a data stream from a client and identify one or more anchor locations of the data stream, wherein the anchor detection hardware is a device dedicated to identifying each anchor location, the anchor detection hardware further configured to transfer the anchor location to a de-duplication module executed by a processor of the storage system, wherein the processor is a separate device from the anchor detection hardware; and

the de-duplication module executed by the processor and configured to;

(i) determine if the anchor location is located in a database, (ii) add the anchor location to the database if the anchor location is not located in the database, and (iii) identify duplicate data and remove the duplicate data if the anchor location is located in the database, where the duplicate data is identified by examining bits preceding the anchor location utilizing a first delta value and examining bits following the anchor location utilizing a second delta value.

11. The system of claim 10 wherein the anchor detection hardware comprises a field programmable gate array.

12. The system of claim 10 wherein the anchor detection hardware comprises a card operatively interconnected with a system bus.

13. The system of claim 10 wherein the data stream comprises a tape backup data stream.

14. The system of claim 10 wherein the anchor detection hardware identifies the one or more anchor locations by performing a rolling hash on the data stream.

15. The system of claim 10 wherein the de-duplication module comprises a portion of a virtual tape library module.