STORAGE SYSTEM AND POWER CONSUMPTION REDUCTION METHOD FOR THE SAME

• US 20090063883A1
• Filed: 01/10/2008
• Published: 03/05/2009
• Est. Priority Date: 08/30/2007
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: MORI, Hajime
• Granted Patent: US 8,135,905 B2
• Time in Patent Office: Days
• US Class Current: 713/324
• CPC Class Codes: G06F 3/0608 Saving storage space on storage systems
• CPC Class Codes: G06F 3/0634 by changing the state or mode of one or more devices
• CPC Class Codes: G06F 3/0641 De-duplication techniques
• CPC Class Codes: G06F 3/0646 Horizontal data movement in storage systems, i.e. moving data in between storage devices or systems
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

This invention achieves data capacity efficiency via data de-duplication and maximizes a power-saving effect by disk operation control. In a storage system, when data is received from a computer, a value representing the bit string for the data is calculated and whether or not a value identical to the calculated value is stored in a data management table is judged. If it is judged that an identical value is not stored, the received data is registered in the data management table and stored, based on a group management table, in disk device(s) associated with a logical unit number of a logical unit constituting an active group. Meanwhile, if it is judged that an identical value is stored, the received data is stored in disk device(s) based on the group information managed in the group management table and the management information managed in the data management table.

Claims

1. A storage system including:

a computer; and

a storage apparatus having a plurality of disk devices storing pieces of data sent from the computer and a plurality of logical units configured from the disk devices, comprising;

a group management table storing group information including at least information for one or more groups configured from the logical units and information on whether or not these groups are active;

a power control unit for switching ON/OFF of the power of the disk devices associated with the logical units in the groups;

a data management table storing management information including;

logical unit numbers for the logical units associated with storage locations of the pieces of data stored in the disk devices;

values representing bit strings for the pieces of data;

and computer-designated numbers associated with the logical units;

a calculation unit for calculating, when receiving a piece of data from the computer, a value representing the bit string for the piece of data;

a judgment unit for judging whether or not a value identical to the value calculated by the calculation unit is stored in the data management table;

a first storing unit for storing, when the judgment unit judges that no identical value is stored, the received piece of data in the data management table and storing it in one or more disk devices associated with a logical unit number of a logical unit constituting an active group, based on the group management table; and

a second storing unit for storing, when the judgment unit judges that an identical value is stored, the received piece of data in one or more of the disk devices based on the group information in the group management table and the management information in the data management table.

2. The storage system according to claim 1, further comprising a un-compared data management table storing un-compared data information including at least the logical unit numbers of logical units temporarily storing pieces of data and values representing the bit strings for the pieces of data, wherein

the second storing unit comprises:

a non-comparison judgment unit for judging whether or not a value identical to the value representing the bit string for the received piece of data is stored in the un-compared data management table;

a un-compared data processing unit for;

storing, when the non-comparison judgment unit judges that an identical value is stored, the received piece of data in one or more disk devices associated with the logical unit number of a logical unit constituting an active group, based on the group management table; and

storing the logical unit number associated with the disk devices storing the received piece of data, and the value representing the bit string for the received piece of data in the un-compared data management table; and

a de-duplication unit for performing, when the non-comparison judgment unit that judges an identical value is not stored, de-duplication processing to prevent the received piece of data from being stored redundantly.

3. The storage system according to claim 2, wherein the de-duplication unit comprises:

a status judgment unit for judging, based on the group management table, whether or not one or more disk devices storing the piece of data having a value identical to the value representing the bit string for the received piece of data, are active;

a data judgment unit for reading, when the status judgment unit judges that the disk devices are active, the piece of data having the identical value from the disk devices, and judging whether or not the read piece of data and the received piece of data match;

a third storing unit for storing, when the data judgment unit judges that the pieces of data match, a computer-designated number for the received piece of data in the data management table, associating it with the logical unit number of the read piece of data; and

a fourth storing unit for storing, when the data judgment unit judges that the above pieces of data do not match, the received piece of data in the disk devices storing the read piece of data and storing the management information for the received piece of data in the data management table.

4. The storage system according to claim 3, wherein:

the de-duplication unit further comprises an activation judgment unit for judging, when the status judgment unit judges that the disk devices are not active, whether or not a group, managed in the group management table, that stores the piece of data having the identical value can be activated;

when the activation judgment unit judges that the group can be activated, the power control unit switches on the power for the disk devices associated with the groups; and

when the power for the disk devices is switched on, the data judgment unit judges whether or not the above pieces of data match.

5. The storage system according to claim 4, wherein the activation judgment unit judges whether or not the group can be activated by comparing a predetermined number of concurrently-active groups and the number of groups currently active.

6. The storage system according to claim 4, wherein the de-duplication unit further comprises a fifth storing unit for storing, when the activation judgment unit judges that the group can not be activated, the received piece of data in one or more disk devices associated with an active group and storing the management information for the received piece of data in the data management table.

7. The storage system according to claim 1, wherein the groups are RAID groups.

8. The storage system according to claim 2, further comprising:

an activation target table storing activation target information including values representing the bit strings of pieces of data, activation target groups, and the counts for the values; and

an optimization unit for performing, when the un-compared data information is stored in the un-compared data management table, optimization processing to relocate the pieces of data having identical values so that they belong to the same group.

9. The storage system according to claim 8, wherein the optimization by the optimization unit is triggered by at least any of the situations of:

when activation/deactivation of a group occurs during normal operation;

when an inactive group is activated;

when the number of un-compared pieces of data stored in the un-compared data management table exceeds a predetermined threshold value; and

when the optimization is designated by a user or the computer.

10. A storage system power consumption reduction method, the storage system including:

a computer; and

a storage apparatus having a plurality of disk devices storing pieces of data sent from the computer and a plurality of logical units configured from the disk devices, wherein

the storage apparatus comprises;

a group management table storing group information including at least information for one or more groups configured from the logical units and information on whether or not these groups are active;

a power control unit for switching ON/OFF of the power of the disk devices associated with the logical units in the groups; and

a data management table storing management information including;

logical unit numbers for the logical units associated with storage locations of the pieces of data stored in the disk devices;

values representing bit strings for the pieces of data; and

computer-designated numbers associated with the logical units; and

the method comprising;

a calculation step of calculating, when receiving a piece of data from the computer, a value representing the bit string for the piece of data;

a judgment step of judging whether or not a value identical to the calculated value is stored in the data management table; and

a first storing step of storing, when it is judged in the judgment step that no identical value is stored, the received piece of data in the data management table and storing it in one or more disk devices associated with a logical unit number of a logical unit constituting an active group, based on the group management table; and

a second storing step of storing, when it is judged in the judgment step that an identical value is stored, the received piece of data in one or more of the disk devices based on the group information in the group management table and the management information in the data management table.

11. The storage system power consumption reduction method according to claim 10, wherein

the storage apparatus further comprises a un-compared data management table storing un-compared data information including at least the logical unit numbers of logical units temporarily storing pieces of data and values representing the bit strings for the pieces of data, and

the second storing step comprises:

a non-comparison judgment step of judging whether or not a value identical to the value representing the bit string for the received piece of data is stored in the un-compared data management table;

a un-compared data processing step for;

storing, when It is judged in the non-comparison judgment step that an identical value is stored, the received piece of data in one or more disk devices associated with the logical unit number of a logical unit constituting an active group, based on the group management table; and

storing the logical unit number associated with the disk devices storing the received piece of data, and the value representing the bit string for the received piece of data in the un-compared data management table; and

a de-duplication step of performing, when it is judged in the non-comparison judgment step that an identical value is not stored, de-duplication processing to prevent the received piece of data from being stored redundantly.

12. The storage system power consumption reduction method according to claim 11, wherein the de-duplication step comprises:

a status judgment step of judging, based on the group management table, whether or not one or more disk devices storing the piece of data having a value identical to the value representing the bit string for the received piece of data, are active;

a data judgment step of reading, when it is judged in the status judgment step that the disk devices are active, the piece of data having the identical value from the disk devices, and judging whether or not the read piece of data and the received piece of data match;

a third storing step of storing, when it is judged in the data judgment step that the pieces of data match, a computer-designated number for the received piece of data in the data management table, associating it with the logical unit number of the read piece of data; and

a fourth storing step of storing, when it is judged in the data judgment step that the above pieces of data do not match, the received piece of data in the disk devices storing the read piece of data and storing the management information for the received piece of data in the data management table.

13. The storage system power consumption reduction method according to claim 12, wherein the de-duplication step further comprises:

an activation judgment step of judging, when it is judged in the status judgment step that the disk devices are not active, whether or not a group, managed in the group management table, that stores the piece of data having the identical value, can be activated, and

wherein

when it is judged in the activation judgment step that group can be activated, the power control unit switches on the power for the disk devices associated with the groups; and

when the power for the disk devices is switched on, the data judgment step includes judging whether or not the above pieces of data match.

14. The storage system power consumption reduction method according to claim 13, wherein the activation judgment step includes judging whether or not the group can be activated by comparing a predetermined number of concurrently-active groups and the number of groups currently active.

15. The storage system power consumption reduction method according to claim 13, wherein the de-duplication step further comprises a fifth storing step of storing, when it is judged in the activation judgment step that the group cannot be activated, the received piece of data in one or more disk devices associated with an active group and storing the management information for the received piece of data in the data management table.

16. The storage system power consumption reduction method according to claim 10, wherein the groups are RAID groups.

17. The storage system power consumption reduction method according to claim 11, wherein:

the storage apparatus further comprises an activation target table storing activation target information including values representing the bit strings for pieces of data, activation target groups, and the counts for the values; and

the method further comprises an optimization step of performing, when the un-compared data information is stored in the un-compared data management table, optimization processing to relocate the pieces of data having identical values so that they belong to the same group.

18. The storage system power consumption reduction method according to claim 17, wherein the optimization step is triggered by at least any of the situations of:

when activation/deactivation of a group occurs during normal operation;

when an inactive group is activated;

when the number of un-compared pieces of data stored in the un-compared data management table exceeds a predetermined threshold value; and

when the optimization is designated by a user or the computer.