STORAGE SYSTEM, AND DATA MIGRATION METHOD FOR THE SAME

• US 20100049917A1
• Filed: 10/20/2008
• Published: 02/25/2010
• Est. Priority Date: 08/25/2008
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: KONO, Yasutaka, Sakashita, Yukinori
• Granted Patent: US 8,024,603 B2
• Time in Patent Office: Days
• US Class Current: 711/114
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

The invention is directed to a storage system including a storage subsystem providing a data storage service to a host computer, and a management device managing the storage subsystem. The management device issues a command to a controller in the storage subsystem for migrating data on a migration-source volume to a migration-destination volume in accordance with a predetermined task. When the migration-destination volume is not available for use for some reason, and when the data migration is not completed normally, the management device searches an alternative volume in accordance with migration-destination requirements including essential and arbitrary requirements, and then issues a command for data migration to thus found alternative volume. With such a configuration, even if a migration-destination volume is not available for use for some reason during data migration, any other volume can be used as a migration destination in accordance with the migration-destination requirement(s).

Claims

1. A storage system, comprising:

at least one storage subsystem that provides a data storage service to a host computer, having a disk array including a plurality of hard disk drives forming a plurality of logical volumes and a controller that controls an access to the disk array based on an access request coming from the host computer; and

a management device that manages the at least one storage subsystem, having migration task information including a first task defining data migration from a first logical volume being any one of the plurality of logical volumes to a second logical volume being any other one of the plurality of logical volumes and migration-destination requirement information including at least one migration-destination requirement about the first task,

wherein the management device issues a first request for executing the first task to a first controller of the at least one storage subsystem including the first logical volume, in accordance with the first task found in the migration task information,

wherein the management device selects a third logical volume from the plurality of logical volumes for a replacement of the second logical volume based on the migration-destination requirement information, when the first task is abnormally completed by the first controller,

wherein the management device enters a second task defining data migration from the first to third logical volume into the migration task information, and

wherein the management device issues a second request for executing the second task to the controller of the at least one storage subsystem including the first logical volume, in accordance with the second task found in the migration task information.

2. The storage system according to claim 1,

wherein the at least one migration-destination requirement is either an essential requirement or an arbitrary requirement.

3. The storage system according to claim 2,

wherein the management device is configured to display the arbitrary requirement determined as not being satisfied to a system manager, when determining that the third logical volume is not satisfying at least one of the arbitrary requirements found in the migration-destination requirement information.

4. The storage system according to claim 2,

wherein the management device stores a third task defining data migration from a fourth logical volume being any one of the plurality of logical volumes to the third logical volume being any other one of the plurality of logical volumes, into the migration task information,

wherein the management device specifies the third task as a conflict task based on the migration task information, when the third logical volume is satisfying all of the essential requirements found in the migration-destination requirement information,

wherein the management device selects a fifth logical volume satisfying a migration-destination requirement about the conflict task from the plurality of logical volumes, and

wherein the management device changes a migration destination for data in the conflict task to the selected fifth logical volume.

5. The storage system according to claim 2,

wherein the management device selects a sixth logical volume satisfying all of the essential requirements about the first task from the plurality of logical volumes, when determining that the third logical volume is not satisfying at least one of the essential requirements found in the migration-destination requirement information, and

wherein the management device enters a fourth task defining data migration from the third to sixth logical volume into the migration task information.

6. The storage system according to claim 5,

wherein the management device includes task execution condition information defining an execution condition specifically for any one of the tasks found in the migration task information, and

wherein the management device enters an execution condition for the third task into the task execution condition information.

7. The storage system according to claim 6, wherein the management device issues, when the execution condition is satisfied, to the controller of the at least one storage subsystem including the third logical volume, a command for executing the third task.

8. The storage system according to claim 7,

wherein the task execution condition information includes an execution deadline for the specific task, and

wherein the management device continuously makes a determination whether the execution condition is satisfied or not until the execution deadline is passed.

9. The storage system according to claim 8, wherein, when determining that the execution condition is not satisfied until the execution deadline is passed, the management device notifies a system manager of execution failure of the third task.

10. The storage system according to claim 2,

wherein the migration-destination requirement is defined based on an attribute of each of the plurality of logical volumes, and

wherein the management device calculates a score based on the migration-destination requirement and the attribute of each of the plurality of logical volumes, and specifies any of the logical volumes showing the highest value of the calculated score as the third logical volume.

11. The storage system according to claim 2,

wherein the management device specifies the task defining data migration to the third logical volume as a conflict task based on the migration task information, when determining that the third logical volume is satisfying all of the essential requirements found in the migration-destination requirement table,

wherein the management device selects a fourth logical volume satisfying a migration-destination requirement for the conflict task from the plurality of logical volumes, and wherein the management device enters a task defining data migration from the third logical volume to the selected fourth logical volume into the migration task table.

12. The storage system according to claim 1,

wherein the storage system includes a first storage subsystem and a second storage subsystem coupled to the first storage subsystem over a network, and

wherein the first storage subsystem includes the first logical volume mapped to a logical volume of the second storage subsystem.

13. The storage system according to claim 12,

wherein the first storage subsystem includes a power supply control section that controls a power supply with respect to the hard disk drives, and

wherein the management device controls the power supply control section to put any of the hard disk drives configuring the first logical volume into a power saving mode, after the first or second task is executed.

14. A data migration method in a storage system including at least one storage subsystem that provides a data storage service to a host computer, and a management device that manages the at least one storage subsystem, the method comprising the steps of:

keeping, by the management device, migration task information including a first task defining data migration from a first logical volume to a second logical volume;

keeping, by the management device, migration-destination requirement information including at least one migration-destination requirement about the first task;

issuing, by the management device, in accordance with the first task found in the migration task information, to a controller of the at least one storage subsystem including the first logical volume, a command for executing the first task;

specifying, by the management device, when determining that the first task is not normally completed by the controller, based on the migration-destination requirement information, a third logical volume for a replacement of the second logical volume;

entering, by the management device, into the migration task information, a second task defining data migration from the first to third logical volume; and

issuing, by the management device, in accordance with the second task found in the migration task information, to the controller of the at least one storage subsystem including the first logical volume, a command for executing the second task.