DATA RESTORING METHOD AND AN APPARATUS USING JOURNAL DATA AND AN IDENTIFICATION INFORMATION

• US 20090089614A1
• Filed: 10/27/2008
• Published: 04/02/2009
• Est. Priority Date: 02/20/2003
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Mogi, Kazuhiko, Oeda, Takashi, Yamamoto, Yasutomo, Eguchi, Yoshiaki, Arai, Kouji
• Granted Patent: US 7,971,097 B2
• Time in Patent Office: Days
• US Class Current: 714/15
• CPC Class Codes: G06F 11/142 Reconfiguring to eliminate the error group management mechanisms in a peer-to-peer network H04L67/1044
• CPC Class Codes: G06F 11/1469 Backup restoration techniques
• CPC Class Codes: G06F 11/1471 involving logging of persistent data for recovery
• CPC Class Codes: Y10S 707/99953 Recoverability

Abstract

A host and a storage system each keep a shared identifier indicating a state of a system. The storage system acquires, at update of data, a data pair including data for a change through processing of the host and data before the update. The storage system relates the data pair to a shared identifier. When the host indicates an identifier, the storage system restores data using the data pair.

Claims

1. A storage system coupled to a computer comprising:

a plurality of physical storages configuring a first logical storage and a second logical storage;

a control unit receiving a read request and a write request from the computer; and

a cache memory temporarily storing a read data to be sent to the computer according to the read request,

wherein the control unit determines that the write request specifies the first logical storage, records a write data corresponding to the write request to the cache memory, and notifies a termination of the write request to the computer,

wherein, after notifying a termination of the write request to the computer, the control unit reads object data which is an object of the write request from a first part of the plurality of physical storages corresponding to the first logical storage, records the object data to the cache memory, and creates a journal data based on the write data and the object data in the cache memory, and

wherein, asynchronously to the creation of the journal data in the cache memory, the control unit records the journal data to a second part of the plurality of physical storages corresponding to the second logical storage.

2. A storage system according to claim 1,

wherein the read data in the cache memory is read from the first part of the plurality of physical storages.

3. A storage system according to claim 2,

wherein the journal data includes an address information that indicates the location of the first logical storage corresponding to the write request.

4. A method for journal data creation in a storage system, coupled to a computer, having a plurality of physical storages, a cache memory, and a control unit, the method comprising the steps of:

configuring a first logical storage and a second logical storage with the plurality of physical storages;

receiving a read request from the computer and temporarily recording a read data in the cache memory according to the read request;

receiving a write request from the computer, determining that the write request specifies the first logical storage, recording a write data corresponding to the write request to the cache memory, and notifying a termination of the write request to the computer;

after notifying a termination of the write request to the computer, reading object data which is an object of the write request from a first part of the plurality of physical storages corresponding to the first logical storage, recording the object data to the cache memory, and creating a journal data based on the write data and the object data in the cache memory; and

recording, asynchronously to the creation of the journal data in the cache memory, the journal data to a second part of the plurality of physical storages corresponding to the second logical storage.

5. A method for journal data creation according to claim 4, further comprising the step of:

reading the read data from the first part of the plurality of physical storages.

6. A method for journal data creation according to claim 5,

wherein the journal data includes an address information that indicates the location of the first logical storage corresponding to the write request.