Data migration in storage system

• US 7,912,814 B2
• Filed: 09/23/2005
• Issued: 03/22/2011
• Est. Priority Date: 05/10/2004
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Shiga, Kenta, Shirogane, Tetsuya, Matsunami, Naoto, Iwami, Naoko
• Primary Examiner(s): Vo; Tim T.
• Assistant Examiner(s): Ahn; Sangwoo
• Application Number:
  US11/234,459
• Publication Number:
  US 20060020663A1
• Time in Patent Office: 2,006 Days
• Field of Search: 707/640, 707/661, 707/696, 707/781, 709/212, 709/225
• US Class Current: 707/640
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0617 in relation to availability
• CPC Class Codes: G06F 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• CPC Class Codes: G06F 3/0637 Permissions
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: H04L 2101/631 Small computer system interface [SCSI] addresses
• CPC Class Codes: H04L 2101/645 Fibre channel identifiers
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]
• CPC Class Codes: Y10S 707/99942 Manipulating data structure, e.g. compression, compaction, compilation

Abstract

A storage system includes a first storage node and a second storage node. The first storage node has a first logical unit to which a first target is set, and the second storage node has a second logical unit.

To migrate data from the first logical unit to the second logical unit, the first storage node forwards data stored in the first logical unit to the second storage node, and the second storage node stores the data into the second logical unit. The first storage node also forwards information about the first target to the second storage node, and the second storage node sets a target to the second logical unit using the received information.

Claims

1. A first storage system coupled to a second storage system, a computer and a name server, the first storage system comprising:

a first port coupled to the computer via an IP network;

a plurality of disk drives on which a first volume is constructed; and

a processor, coupled to the first port and the plurality of disk drives, which assigns the first volume to the first port, receives, directly from the second storage system without being passed through the computer, a target name that is used in the second storage system, assigns the target name to a set of the first port and the first volume in the first storage system, and sends information of the target name to the name server when a data migration from the second storage system directly to the first storage system is executed,

wherein the name server notifies the computer of the information of the target name after receiving notification of the target name from the first storage system by using the iSCSI protocol,

wherein the first port accepts an access request from the computer to the first volume after sending the information of the target name to the name server by using an iSCSI protocol if the access request includes the target name, and

wherein the first storage system receives accesses from the computer to the first volume instead of a second volume in the second storage system based on the target name after executing the data migration and after the computer receives notification of the target name from the name server by the iSCSI protocol, whereby neither an operating system of the computer nor an application operating on the computer acknowledges the data migration from the second storage system to the first storage system.

2. A storage system according to claim 1, wherein the information of the target name includes relation information between the target name and the set of the first port and the first volume.

3. A storage system according to claim 2, wherein the processor receives the target name from the second storage system when the data migration is executed.

4. A storage system according to claim 2, wherein the processor receives the target name from the second storage system before the data migration is executed.

5. A storage system according to claim 2, wherein the processor receives the target name from the second storage system after the data migration is executed.

6. A storage system according to claim 1, wherein the processor assigns the target name to the set of the first port and the first volume if the first storage system receives an instruction from the second storage system.

7. A storage system according to claim 6, wherein data to be migrated by the data migration and stored in the first volume is stored in the second volume of the second storage system before execution of the data migration and the target name is assigned to the second volume before execution of the data migration.

8. A storage system according to claim 6, wherein the instruction includes information of a relationship between a port of the computer and the target name.

9. A storage system according to claim 8, wherein the processor sends the information of the target name to the name server by using a State Change Notification command.

10. A storage system according to claim 9, wherein the access request is a log-in command from the computer.

11. A storage system according to claim 10, wherein the first storage system receives the instruction after disconnecting a TCP connection between the computer and the second storage system.