Apparatus for reallocating logical to physical disk devices using a storage controller and method of the same

• US 8,898,383 B2
• Filed: 09/15/2011
• Issued: 11/25/2014
• Est. Priority Date: 04/08/1996
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yamamoto, Yasutomo, Yamamoto, Akira, Satoh, Takao
• Primary Examiner(s): Bragdon, Reginald G.
• Assistant Examiner(s): Ruiz, Aracelis
• Application Number:
  US13/233,610
• Publication Number:
  US 20120005447A1
• Time in Patent Office: 1,167 Days
• Field of Search: 711/165, 711/114, 711/203
• US Class Current: 711/114
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 11/2005 using redundant communication controllers
• CPC Class Codes: G06F 11/2007 using redundant communication media
• CPC Class Codes: G06F 11/201 between storage system components
• CPC Class Codes: G06F 11/2087 with a common controller
• CPC Class Codes: G06F 11/2089 Redundant storage control functionality
• 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 2211/104 Metadata, i.e. metadata associated with RAID systems with parity
• CPC Class Codes: G06F 3/0605 by facilitating the interaction with a user or administrator
• CPC Class Codes: G06F 3/0607 by facilitating the process of upgrading existing storage systems, e.g. for improving compatibility between host and storage device
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0611 in relation to response time
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/0631 by allocating resources to storage systems
• CPC Class Codes: G06F 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• 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 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0653 Monitoring storage devices or systems
• 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 3/0683 Plurality of storage devices
• CPC Class Codes: G06F 3/0685 : Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays
• CPC Class Codes: G06F 3/0689 : Disk arrays, e.g. RAID, JBOD

Abstract

A storage controller calculates an access frequency of each logical disk; that is selects a first logical disk device of which the access frequency exceeds a first predetermined value, the first logical disk device being allocated to a first physical disk device; selects a second logical disk device which has the access frequency equal to or less than a second predetermined value, the second logical disk device being allocated to a second physical disk device; and reallocates the first and second logical device; and reallocates the first and second logical devices to the second and the first physical disk device, respectively.

Claims

1. A storage system comprising:

a plurality of physical memory devices storing data of a plurality of logical devices configuring RAID (Redundant Arrays of Inexpensive Disks); and

a storage controller coupled to the plurality of physical memory devices,

wherein each of the plurality of logical devices is a target device of an access from a data processing unit coupled to the storage system, and

at least two of the plurality of physical memory devices differ in performance,

wherein the storage controller is configured to reallocate data having a high access frequency to one of the plurality of physical memory devices having a better performance than the physical memory device in which the data to be reallocated is currently stored, and

wherein a size of a data unit to be reallocated by the storage controller is set based on a least common multiple of an amount of data corresponding to a check information of the RAID configuration of both logical devices between which the data is to be reallocated and is larger than a data unit to be accessed from the data processing unit.

2. A storage system according to claim 1,

wherein the difference in performance is a difference in operation speed, and

the storage controller is configured to reallocate the data having the high access frequency to one of the plurality of physical memory devices having a higher speed than the physical memory device of the plurality of physical memory devices in which the data to be reallocated is currently stored.

3. The storage system according to the claim 2,

wherein the storage controller determines to reallocate the data having the high access frequency when an access frequency of the data is equal to or more than a predetermined value and one of the plurality of physical memory devices has a higher speed than the physical memory device of the plurality of physical memory devices in which the data to be reallocated is currently stored.

4. The storage system according to the claim 2,

wherein the storage controller is further configured to reallocate data having a low access frequency to one of the plurality of physical memory devices having a lower speed than the physical memory device of the plurality of physical memory devices in which the data to be reallocated is currently stored.

5. The storage system according to the claim 4,

wherein the storage controller determines to reallocate the data having the low access frequency when the access frequency of the data is equal to or less than a predetermined value.

6. The storage system according to the claim 2,

wherein the data in the logical device are consecutively arranged in the physical memory devices.

7. The storage system according to claim 1,

wherein the difference in performance is a difference in sequential access ratio, and

the storage controller is configured to reallocate the data having the high access frequency to one of the plurality of physical memory devices having a higher sequential access ratio than the physical memory device of the plurality of physical memory devices in which the data to be reallocated is currently stored.

8. A reallocation method, in a storage system having a plurality of physical memory devices, a storage controller coupled to the plurality of physical memory devices, and a data processing unit coupled to the control unit, the reallocation method comprising the steps of:

storing data of a plurality of logical devices configuring RAID (Redundant Arrays of Inexpensive Disks) to the plurality of physical memory devices, where at least two of the plurality of physical memory devices differ in performance and each of the plurality of logical devices is a target device of an access from the data processing unit; and

reallocating data having a high access frequency to one of the plurality of physical memory devices having a better performance than the physical memory device of the physical memory devices in which the data to be reallocated is currently stored,

wherein a size of a data unit to be reallocated is set based on a least common multiple of an amount of data corresponding to a check information of the RAID configuration of both logical devices between which the data is to be reallocated and is larger than a data unit to be accessed from the data processing unit.

9. The reallocation method of claim 8,

wherein the difference in performance is a difference in operation speed, and

further comprising the step of:

reallocating the data having the high access frequency to one of the plurality of physical memory devices having a higher speed than the physical memory device of the plurality of physical memory devices in which the data to be reallocated is currently stored.

10. The reallocation method of claim 9,

wherein the data having the high access frequency is reallocated when an access frequency of the data is equal to or more than a predetermined value and one of the plurality of physical memory devices has a higher speed than the physical memory device of the plurality of physical memory devices in which the data to be reallocated is currently stored.

11. The reallocation method of claim 9, further comprising:

reallocating data having a low access frequency to one of the plurality of physical memory devices having a lower speed than the physical memory device of the plurality of physical memory devices in which the data to be reallocated is currently stored.

12. The reallocation method of claim 11,

wherein the data having the low access frequency is reallocated when the access frequency of the data is equal to or less than a predetermined value.

13. The reallocation method of claim 9,

wherein the data in the logical device are consecutively arranged in the physical memory devices.

14. The reallocation method of claim 8,

wherein the difference in performance is a difference in sequential access ratio, and

further comprising the step of:

reallocating the data having the high access frequency to one of the plurality of physical memory devices having a higher sequential access ratio than the physical memory device of the plurality of physical memory devices in which the data to be reallocated is currently stored.