Storage controller and duplicated data detection method using storage controller

• US 8,495,288 B2
• Filed: 06/10/2008
• Issued: 07/23/2013
• Est. Priority Date: 04/02/2008
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Hosoya, Mutsumi, Kanayama, Hiroshi, Mineta, Wataru
• Primary Examiner(s): DUDEK JR, EDWARD J
• Application Number:
  US12/136,108
• Publication Number:
  US 20090254507A1
• Time in Patent Office: 1,869 Days
• Field of Search: 711/112, 711/162, 711/216, 711/E12.002, 707/664
• US Class Current: 711/112
• CPC Class Codes: G06F 11/1453 using de-duplication of the data
• CPC Class Codes: G06F 11/1456 Hardware arrangements for backup
• CPC Class Codes: G06F 11/2071 using a plurality of controllers
• CPC Class Codes: G06F 11/2089 Redundant storage control functionality
• CPC Class Codes: G06F 12/0866 for peripheral storage systems, e.g. disk cache
• CPC Class Codes: G06F 2201/84 Using snapshots, i.e. a logical point-in-time copy of the data
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0641 De-duplication techniques
• CPC Class Codes: G06F 3/0652 Erasing, e.g. deleting, data cleaning, moving of data to a wastebasket
• CPC Class Codes: G06F 3/0683 Plurality of storage devices

Abstract

A storage controller of the present invention narrows down the target for data comparison by comparing hash codes beforehand and rapidly detects duplicated data. A hash value setting unit sets a hash code in data received from a host. Hash code-attached data is stored in a logical volume. A microprocessor unit compares the hash codes for each comparison-targeted data. When hash codes match with one another, a data comparator compares the target data, and determines whether or not the data is duplicated data. When duplicated data is detected, the microprocessor unit removes the duplicated data.

Claims

1. A storage system comprising:

a first storage controller including;

a first communications controller for carrying out data communications with a host computer;

a second communications controller for carrying out data communications with a storage device;

a cache memory that is used in the exchange of data between the first communications controller and the second communications controller, wherein said cache memory is used for both write and read operations;

a controller for controlling the first communications controller, the second communications controller and the cache memory respectively;

a determination data setting unit for setting, in respective data, and determination data for making a primary determination as to whether or not the respective data matches with other data;

a second storage controller including;

a duplicated data detector, which is for detecting whether or not a plurality of prescribed data is duplicated data, and which comprises a primary determination unit that makes a primary determination as to whether or not the respective prescribed data match with one another by comparing the respective determination data set in the respective prescribed data, and a secondary determination unit that compares the respective prescribed data and makes a secondary determination as to whether or not the respective prescribed data is duplicated data when the primary determination unit makes a primary determination that the respective prescribed data match with one another; and

a duplicated data processor that implements a preconfigured prescribed process for the duplicated data, when a secondary determination is that the respective prescribed data is duplicated data,

wherein at least the determination data setting unit and the secondary determination unit are configured as dedicated circuits that are separate from the controller,

wherein said determination data setting unit provides a hash value of write data received from said host computer to said cache memory,

wherein the first controller stores the write data received from said host computer with the hash value of the write data to the storage device, and the second storage controller receives the write data received from said host computer with the hash value of the write data, and

wherein the duplicated data processor stores only one data of the duplicated data to a differential backup volume coupled to the second storage controller, and deletes the other data of the duplicated data.

2. The storage system according to claim 1, wherein the duplicated data detector executes the primary determination by comparing the respective determination data set in the respective prescribed data when the respective prescribed data is transferred to the cache memory, and makes the secondary determination as to whether or not the respective prescribed data is the duplicated data by respectively reading out from the cache memory and comparing the respective prescribed data when the primary determination is that the respective prescribed data match with one another.

3. The storage system according to claim 1, wherein the duplicated data processor transfers any newer data of the respective prescribed data to a prescribed storage area when the respective prescribed data is not the duplicated data.

4. A storage system, comprising:

a first storage controller including;

a first communications controller for carrying out data communications with a host computer;

a second communications controller for carrying out data communications with a storage device;

a cache memory that is used in the exchange of data between the first communications controller and the second communications controller, wherein said cache memory is used for both write and read operations;

a controller for controlling the first communications controller, the second communications controller and the cache memory respectively;

a determination data setting unit for setting, in respective data, and determination data for making a primary determination as to whether or not the respective data matches with other data;

a second storage controller including;

a duplicated data detector, which is for detecting whether or not a plurality of prescribed data is duplicated data, and which comprises a primary determination unit that makes a primary determination as to whether or not the respective prescribed data match with one another by comparing the respective determination data set in the respective prescribed data, and a secondary determination unit that compares the respective prescribed data and makes a secondary determination as to whether or not the respective prescribed data is duplicated data when the primary determination unit makes a primary determination that the respective prescribed data match with one another; and

a duplicated data processor that implements a preconfigured prescribed process for the duplicated data, when a secondary determination is that the respective prescribed data is duplicated data,

wherein at least the determination data setting unit and the secondary determination unit are configured as dedicated circuits that are separate from the controller,

wherein said determination data setting unit provides a hash value of write data received from said host computer to said cache memory, wherein the first controller stores the write data received from said host computer with the hash value of the write data to the storage device, and the second storage controller receives the write data received from said host computer with the hash value of the write data, and

wherein the duplicated data processor stores only one data of the duplicated data to a differential backup volume coupled to the second storage controller, sets link information to the one data in the other data of the duplicated data, and wherein the second storage controller is located in a remote site from the first storage controller.

5. The storage system according to claim 4, wherein the duplicated data detector executes the primary determination by comparing the respective determination data set in the respective prescribed data when the respective prescribed data is transferred to the cache memory, and makes the secondary determination as to whether or not the respective prescribed data is the duplicated data by respectively reading out from the cache memory and comparing the respective prescribed data when the primary determination is that the respective prescribed data match with one another.

6. The storage system according to claim 4, wherein the duplicated data processor transfers any newer data of the respective prescribed data to a prescribed storage area when the respective prescribed data is not the duplicated data.