Manipulating data in a data storage device using an auxiliary memory device

• US 7,383,379 B2
• Filed: 08/07/2002
• Issued: 06/03/2008
• Est. Priority Date: 08/07/2002
• Status: Active Grant

• Current Assignee: HTC Corporation
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Patterson, Brian L, Diamond, Bryan, Condel, Jonathan
• Primary Examiner(s): Song; Jasmine
• Application Number:
  US10/214,685
• Publication Number:
  US 20040030831A1
• Time in Patent Office: 2,127 Days
• Field of Search: 711/4, 711/104, 711/113, 711/114, 711170-173, 714/6, 714/7
• US Class Current: 711/114
• CPC Class Codes: G06F 11/1096 Parity calculation or recalculation after configuration or reconfiguration of the system
• CPC Class Codes: G06F 2211/1004 Adaptive RAID, i.e. RAID system adapts to changing circumstances, e.g. RAID1 becomes RAID5 as disks fill up
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0689 Disk arrays, e.g. RAID, JBOD

Abstract

A data storage device having, for example, a disk array comprising a plurality of independent disks, an array controller for controlling the array and an auxiliary memory device connected to the disk array and array controller for temporarily storing data being moved within the array or being changed from a first data storage type to a second data storage type within the array.

Claims

1. A data storage device comprising:

a disk array comprising a plurality of independent disks that include a first location with a first RAID (Redundant Arrays of Independent Disks) type and a second location with a second RAID type;

an array controller for controlling said disk array; and

an auxiliary memory device connected to said disk array and said array controller for temporarily storing data outside of said disk array when said data is being changed from said first RAID type to said second RAID type within said disk array, wherein said array controller writes said data to the first location as the first RAID type, transfers said data from the first location to the auxiliary memory, reallocates said first location from said first RAID type to said second RAID type while said data is temporarily stored in said auxiliary memory, and then writes said data back to the first location as the second RAID type.

2. The data storage device of claim 1, wherein said auxiliary memory device is a Random Access Memory (RAM) unit.

3. The data storage device of claim 1, wherein said first RAID type is RAID Type-1 and said second RAID type is RAID Type-5.

4. The data storage device of claim 1, wherein said auxiliary memory device is only used when said disk array reaches a predetermined level of data storage.

5. The data storage device of claim 1, wherein said disks of said disk array are allocated in stripes among different data storage types.

6. A method of changing a first set of data in a disk array from a first storage type to a second storage type, said method comprising:

writing data to a first location of the first storage type;

copying said data from the first location of said first storage type within said disk array to an auxiliary memory device;

reallocating said first location from said first storage type to said second storage type after said data is copied to said auxiliary memory device; and

copying said data from said auxiliary memory device back to said first location under said second storage type in order to change said data in said disk array from said first storage type to said second storage type, wherein copying said data from said auxiliary memory device back to said first location under said second storage type comprises rewriting said data from said auxiliary memory device to said first location within said disk array.

7. The method of claim 6, further comprising copying said data from said auxiliary memory devise to a second location of said second storage type within said disk array.

8. The method of claim 6, further comprising:

evaluating a size of said first set of data relative to a granularity with which said array is allocated between said first and second storage types to produce an evaluation; and

,

in response to said evaluation, selectively reallocating said first location from said first storage type to said second storage type after said data is copied to said auxiliary memory device, wherein copying said data from said auxiliary memory device back to said disk array under said second storage type comprises copying said data from said auxiliary memory device to said first location within said disk array.

9. A method of changing a first set of data in a disk array from a first storage type to a second storage type, said method comprising:

copying said data from a first location of said first storage type within said disk array to an auxiliary memory device;

copying said data from said auxiliary memory device back to said disk array under said second storage type in order to change said data in said disk array from said first storage type to said second storage type;

identifying a second set of data at a second location of said second storage type within said array, wherein said data can be changed from said second storage type to said first storage type;

copying said second set of data to said auxiliary memory device;

copying said second set of data to said first location within said array; and

copying said first set of data to said second location within said array.

10. A method of balancing performance of a disk array, said method comprising:

copying a first set of data from a first, actively used disk having a first RAID (Redundant Arrays of Independent Disks) storage type within said disk array to an auxiliary memory unit;

copying a second set of data from a second, less actively used disk having a second RAID storage type within said disk array to said auxiliary memory device;

copying said first set of data to said second disk to change said first set of data to said second RAID storage type; and

copying said second set of data to said first disk to change said second set of data to said first RAID storage type.

11. A data storage device comprising:

a data storage device including an array controller coupled to an array of independent disks with first plural disks storing data having a first RAID (Redundant Arrays of Independent Disks) type and second plural disks having a second RAID type; and

an auxiliary memory device separate from, but in communication with said data storage device for receiving said data stored in the first plural disks so as to temporarily store said data outside said data storage device while said first plural disks are being changed from said first RAID type to said second RAID type within said data storage device, wherein said array controller reallocates said first plural disks from said first RAID type to said second RAID type while said data is temporarily stored in said auxiliary memory and then transfers said data back to the first plural disks having said second RAID type.

12. The data storage device of claim 11, wherein said auxiliary memory device is a RAM (Random Access Memory) unit.

13. The data storage device of claim 11, wherein said auxiliary memory device comprises any of a disk drive, a hard drive, a tape drive or semiconductor memory.

14. A system for changing a first set of data in a disk array from a first storage type to a second storage type, said system comprising:

means for copying said data from a first location of said first storage type within said disk array to an auxiliary memory means;

means for copying said data from said auxiliary memory means back to said disk array under said second storage type in order to change said data in said disk array from said first storage type to said second storage type;

means for identifying a second set of data at a second location of said second storage type within said array, wherein said data can be changed from said second storage type to said first storage type;

means for copying said second set of data to said auxiliary memory means;

means for copying said second set of data to said first location within said array; and

means for copying said first set of data to said second location within said array.

15. The system of claim 14, further comprising means for reallocating said first location from said first storage type to said second storage type after said data is copied to said auxiliary memory means.

16. The system of claim 14, further comprising means for copying said data from said auxiliary memory means to a second location of said second storage type within said disk array.

17. The system of claim 14, further comprising:

means for evaluating a size of said first set of data relative to a granularity with which said array is allocated between said first and second storage types to produce an evaluation; and

,

in response to said evaluation, means for selectively reallocating said first location from said first storage type to said second storage type after said data is copied to said auxiliary memory means, wherein copying said data from said auxiliary memory means back to said disk array under said second storage type comprises copying said data from said auxiliary memory means to said first location within said disk array.

18. A data storage device comprising:

a disk array comprising a plurality of independent disks;

an array controller for controlling said disk array; and

an auxiliary memory device in communication with said disk array and array controller;

wherein said device is configured to temporarily store data in said auxiliary memory from a first location in said disk array when said data is being changed from a first data storage type to a second data storage type within said disk array;

wherein said array controller evaluates a size of said data relative to a granularity with which said disk array is allocated between said first and second data storage types to produce an evaluation and, in response to said evaluation, selectively reallocates said first location from said first data storage type to said second data storage type after said data is copied to said auxiliary memory device, wherein copying said data from said auxiliary memory device back to said disk array under said second storage type comprises copying said data from said auxiliary memory device to said first location within said disk array.

19. The data storage device of claim 18, wherein said auxiliary memory device is a Random Access Memory (RAM) unit.

20. The data storage device of claim 18, wherein said first data storage type is Type-1 storage for Redundant Arrays of Independent Disks (RAID);

and said second data storage type is (RAID) Type-5.

21. The data storage device of claim 18, wherein said auxiliary memory device is only used when said disk array reaches a predetermined level of data storage.