Storage control apparatus, data management system and data management method

• US 20070271413A1
• Filed: 09/22/2006
• Published: 11/22/2007
• Est. Priority Date: 09/22/2005
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Fujibayashi, Akira, Nakamura, Shuji, Fujimoto, Kazuhisa
• Granted Patent: US 7,549,016 B2
• Time in Patent Office: Days
• US Class Current: 711/112
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/0616 in relation to life time, e.g. increasing Mean Time Between Failures [MTBF]
• CPC Class Codes: G06F 3/0625 Power saving in storage systems
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0649 Lifecycle management
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: G06F 3/0685 Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A storage control apparatus according to the present invention includes a plurality of connecting units connected to one or more host computers and one or more hard disk drives as storage media for storing data, one or more non-volatile storage media which are of a different type from the hard disk drives and which store data WRITE requested from the host computer, a plurality of processing units for processing WRITE and READ requests from the host computer by using the hard disk drives or the non-volatile storage media and, a plurality of memory units for storing control information to be by the processing units.

Claims

1. A storage control apparatus comprising:

a plurality of connecting units connected to one or more host computers and one or more hard disk drives as storage media for storing data;

one or more non-volatile storage media which are a different type of storage medium from that of the hard disk drives and which stores data WRITE requested from the host computer;

a plurality of processing units for processing WRITE and READ requests from the host computer by using the hard disk drives or the non-volatile storage medium and;

a plurality of memory units for storing control information to be used by the processing units;

wherein,

the hard disk drives are provided as a separate unit or part of a disk array device having control units;

the control information stored in each memory unit is a usage status management table that associates an identifier for each storage medium with information on a usage status of each storage medium;

each memory unit further stores each threshold value for the information on the usage status of each storage medium; and

each processing unit inquires the usage status management table and each threshold value, both of which are stored in each memory unit, and migrates data stored in one of the storage media of either type whose usage status exceeds the threshold value for the usage status to one of the storage media of the other type if any of the information on the usage status exceeds the threshold value thereof.

2. The storage control apparatus according to claim 1, wherein each non-volatile storage medium comprises a flash memory.

3. The storage control apparatus according to claim 1, wherein each non-volatile storage medium comprises a ferroelectric memory.

4. The storage control apparatus according to claim 1, wherein each non-volatile storage medium comprises a phase change memory.

5. The storage control apparatus according to claim 1, wherein each processing unit rotates or stops the hard disk drive by using MAID (Massive Array of Idle Disks) scheme directly or via the control units of the disk array device.

6. The storage control apparatus according to claim 5, wherein the hard disk drive comprises at least either of a SCSI (small Computer System Interface) disk drive or an ATA (AT Attachment) disk drive.

7. The storage control apparatus according to claim 1, wherein,

each non-volatile storage medium has less rewritable cycles than those of the hard disk drive;

the usage status management table includes cycles of rewriting as information on the usage status for each storage medium;

each memory unit stores a threshold value for the cycles of rewriting as the threshold value; and

each processing unit inquires the usage status management table and the threshold value for the cycles of rewriting, both of which are stored in each memory unit, and migrates data stored in one of the storage media of either type whose cycles of rewriting exceeds the threshold value for the cycles of rewriting to one of the storage media of the other type if any of the information on the cycles of rewriting exceeds the threshold value thereof.

8. The storage control apparatus according to claim 1, wherein,

the hard disk drive has lower read/write response speed than that of each non-volatile storage medium;

the usage status management table includes usage cycles of writing data or reading data as information on the usage status of each storage medium;

each memory unit stores a threshold value for the usage cycles of writing data or reading data as the threshold value; and

each processing unit inquires the usage status management table and the threshold value for the usage cycles of writing data or reading data, both of which are stored in each memory unit, and migrates data stored in one of the storage media of either type whose usage cycles of writing data or reading data exceeds the threshold value for the usage cycles of writing data or reading data to one of the storage media of the other type if any of the information on the usage cycles of writing data or reading data exceeds the threshold value thereof.

9. The storage control apparatus according to claim 1, wherein,

the usage status management table includes the number of faulty areas as information on the usage status of each storage medium;

each memory unit stores a threshold value for the number of faulty areas as the threshold value; and

each processing unit inquires the usage status management table and the threshold value for the number of faulty areas, both of which are stored in each memory unit, and migrates data stored in one of the storage media of either type whose the number of faulty areas exceeds the threshold value for the number of faulty areas to one of the storage media of the other type if any of the information on the number of faulty areas exceeds the threshold value thereof.

10. The storage control apparatus according to claim 1, wherein,

if the storage medium of the other type which is a data migration destination is one of the non-volatile storage media, each processing unit secures a certain area on the hard disk drive as a temporary storage area and copies the data to be migrated, part by part in succession, to the temporary storage area on the hard disk drive;

and

when receiving a READ request for part of the data from the host computer during the data migration operation, the processing unit resends corresponding data stored in the storage medium of the data migration source to the host computer, and asynchronously processes the data migration, part by part in succession, to the storage medium of the data migration destination.

11. The storage control apparatus according to claim 1, wherein,

if the storage medium of the other type which is a data migration destination is one of the non-volatile storage media, each processing unit secures a certain area on the hard disk drive as a temporary storage area and copies the data to be migrated, part by part in succession, to the temporary storage area on the hard disk drive;

and

when the processing unit receives a READ request for part of the data from the host computer during the data migration operation, and if new data corresponding to the part of the data is already stored in one of the non-volatile storage media by another WRITE request from the host computer, the processing unit resends the new data to the host computer.

12. The storage control apparatus according to claim 1, wherein,

if the storage medium of the other type which is a data migration destination is one of the non-volatile storage media, each processing unit secures a certain area on the hard disk drive as a temporary storage area;

and

when the processing unit receives a WRITE request for part of the data from the host computer, the processing unit stores new data corresponding to the part of the data stored in the temporary area on the temporary storage area, and the processing unit reflects the new data on the non-volatile storage medium after the migration of the data is completed.

13. The storage control apparatus according to claim 1, wherein,

the usage status management table includes the number of times of erase operation errors as information on the usage status for each storage medium;

each memory unit stores a threshold value for the number of times of erase operation errors as the threshold value; and

each processing unit inquires the usage status management table and the threshold value for the number of times of erase operation errors, both of which are stored in each memory unit, and migrates data stored in one of the storage media of either type whose number of times of erase operation errors exceeds the threshold value for the number of times of erase operation errors to one of the storage media of the other type if any of the information on the number of times of erase operation errors exceeds the threshold value thereof.

14. The storage control apparatus according to claim 1, wherein,

the usage status management table includes average erase time as information on the usage status for each storage medium;

each memory unit stores a threshold value for the average erase time as the threshold value; and

each processing unit inquires the usage status management table and the threshold value for the average erase times, both of which are stored in each memory unit, and migrates data stored in one of the storage media of either type whose average erase time exceeds the threshold value for the average erase time to one of the storage media of the other type if any of the information on the average erase time exceeds the threshold value thereof.

15. A data management system comprising:

the storage control apparatuses according to claim 1;

and

at least one management terminal connected to storage control apparatuses; and

wherein,

the management terminal has a management terminal processing unit and a management terminal storage unit;

the management terminal storage unit stores a general information table including power consumption amount per a certain time period for each storage control apparatus and a threshold value for total power consumption amount per a certain time period of the storage control apparatuses; and

the management terminal processing unit inquires the general information table and calculates the total power consumption amount per a certain time period of the storage control apparatuses, and if the calculated power consumption amount exceeds the threshold value for the total power consumption per a certain time period over the entire storage control apparatuses, data migration is performed between the storage media within the storage control apparatus, or between the storage media among the storage control apparatuses so as to reduce the power consumption per a certain time period.

16. The data management system according to claim 15, wherein the general information table includes a free area of the storage media with lower power consumption in each storage control apparatus.

17. A data management method performed by at least one storage control apparatus, the apparatus comprising:

a plurality of connecting units connected to one or more host computers and one or more hard disk drives as storage media for storing data, one or more non-volatile storage media which are of a different type from the hard disk drives and which store data WRITE requested from the host computer, a plurality of processing units for processing WRITE and READ requests from the host computer by using the hard disk drive or the non-volatile storage medium and, and a plurality of memory units for storing control information to be used by the processing units;

the method comprising;

storing in each memory unit the information which is a usage status management table associating each identifier for each storage medium with information on the usage status of each storage medium;

further storing in each memory unit each threshold value for the information on the usage status of each storage medium;

inquiring on each processing unit the usage status table and each threshold value, both of which are stored in the memory unit, and migrating data stored in one of the storage media of either type whose usage status exceeds the threshold value for the usage status to one of the storage media of the other type if any of the information on the usage status of each storage medium exceeds the threshold value thereof.

18. The data management method according to claim 17, wherein the data management is performed by using each non-volatile storage medium which is a flash memory.

19. The data management method according to claim 17, wherein the data management is performed by using:

each non-volatile storage medium having less rewritable cycles than those of each hard disk drive;

the usage status management table including cycles of rewriting as information on the usage status of each storage medium,

each memory unit storing a threshold value for the cycles of rewriting as the threshold value; and

each processing unit inquiring the usage status management table and the threshold value for the cycles of rewriting, both of which are stored in each memory unit, and migrating data stored in one of the non-volatile storage media that exceeds the threshold value for the cycles of rewriting to one of the hard disk drives.

20. The data management method according to claim 17, wherein the data management is performed by using:

each hard disk drive having a slower read/write response speed than that of each non-volatile storage medium;

the usage status management table including usage cycles of read/write as information for the usage status for each storage medium;

each memory unit storing a threshold value for the usage cycles of read/write as the threshold value; and

each processing units inquiring the usage status management table and the threshold value both of which are stored in each memory unit, and migrating data stored in one of the storage media of either type whose usage cycles of read/write exceeds the threshold value for the usage cycles of read/write to one of the storage media of the other type if any of the information on the usage cycles of read/write of each storage medium exceeds the threshold value thereof.

21. A storage control apparatus comprising:

a plurality of connecting units connected to one or more host computers and one or more disk drives as storage media for storing data;

one or more non-volatile storage media which are a different type of storage media from that of the disk drives and which stores data WRITE requested from the host computer;

a plurality of processing units for processing WRITE and READ requests from the host computer by using the disk drives or the non-volatile storage media and;

a plurality of memory units that store;

a user-specification table for storing identification information on performance of storage media that a user specifies for data,

a storage media management table for associating the storage media with performance thereof; and

a usage status management table for associating an identifier for each storage medium with information on a usage status of each storage medium;

wherein

the processing units inquire the user-specification table and determine a user-specification for the data,

inquire the storage media management table and the usage status management table and select storage media having performance that satisfies the user-specification for the data, and

store the data on the selected storage media.

22. The storage control apparatus according to claim 21, wherein

the processing units, if receiving from the user an instruction to create logical storage area for storing the data,

inquire the storage media management table and the usage status management table and select storage media that satisfies the user-specification for the logical storage area for storing the data, and

creates the logical storage area for storing the data by use of the selected storage media and store the data on the created logical storage area.

23. The storage control apparatus according to claim 21, wherein the non-volatile storage media comprise flash memories.

24. The storage control apparatus according to claim 21, wherein the identification information on performance of the storage media that are stored on the user-specification table comprises information on any of capacities of the data, read frequencies of the data, and whether or not WORM (Write Once Read Many) is specified for the data.

25. The storage control apparatus according to claim 21, wherein

the user-specification table stores identification information on performance of a plurality of storage media, having priorities specified by the user, and

the processing units

inquire the user-specification table and the storage media management table and the usage status management table and select storage media that are specified for the data by the user in accordance with the priorities, and

store the data on the selected storage media.