STORAGE APPARATUS AND STORAGE CONTROL METHOD FOR THE SAME

• US 20120023292A1
• Filed: 07/22/2010
• Published: 01/26/2012
• Est. Priority Date: 07/22/2010
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Saito, Kenichi, Chikusa, Takashi, Kumasawa, Hiroyuki, Hirano, Kazuya
• Granted Patent: US 8,656,099 B2
• Time in Patent Office: Days
• US Class Current: 711/114
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3268 Power saving in hard disk drive
• CPC Class Codes: G06F 3/061 Improving I/O performance
• CPC Class Codes: G06F 3/0625 Power saving in storage systems
• CPC Class Codes: G06F 3/0644 Management of space entities, e.g. partitions, extents, pools
• CPC Class Codes: G06F 3/0665 at area level, e.g. provisioning of virtual or logical volumes
• 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 3/0689 Disk arrays, e.g. RAID, JBOD
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A storage apparatus and its control method capable of implementing thin provisioning and reducing power consumption of storage devices are provided.

A storage apparatus classifies a plurality of storage devices, which provide a pool with a storage resource, into a plurality of groups; performs thin provisioning operation by setting some of the plurality of groups to an active mode, in which the storage devices belonging to the groups are made to enter an activated state; sets other groups to a power-saving mode in which the storage devices are made to enter a power-saving state; and sequentially switches between the group(s) in the active mode and the group(s) in the power-saving mode among the plurality of groups.

Claims

1. A storage apparatus comprising:

a virtual volume accessed by a host computer;

a storage pool having a storage resource associated with the virtual volume; and

a controller for controlling allocation of a storage area from the storage resource in response to write access from the host computer to the virtual volume;

wherein a plurality of storage devices that provide the storage pool with the storage resource constitute a plurality of first groups according to a RAID system and constitute a plurality of second groups including one or more first groups; and

wherein the controller sets some of the plurality of second groups to an active mode in which the storage devices belonging to the some groups are made to enter an activated state;

sets other groups, excluding a group which is set to the active mode from among the plurality of second groups, to a power-saving mode in which the storage devices belonging to those other groups are made to enter a power-saving state;

sequentially switches between the group, which is set to the active mode, and the group, which is set to the power-saving mode, from among the plurality of second groups; and

stores data by allocating a storage area from the storage resource for the second group in the active mode in response to write access by the host computer to the virtual volume.

2. The storage apparatus according to claim 1, wherein the controller allocates the storage area to an access area of the virtual volume in response to the write access from the host computer to the virtual volume so that load will be imposed equally on the storage resource belonging to the second group in the active mode.

3. The storage apparatus according to claim 1, wherein the storage resource of the storage pool is provided from storage devices classified in a specified tier.

4. The storage apparatus according to claim 3, wherein there are a plurality of storage pools and each storage pool has a storage resource of storage devices classified into different tiers.

5. The storage apparatus according to claim 1, wherein the controller sets a threshold;

compares an increase of an allocated amount of the storage area after the second group already in the active mode is set to active, with the threshold; and

changes the status of the next second group from the power-saving mode to the active mode and the status of the second group already in the active mode to the power-saving mode if the controller detects that the allocated amount has reached the threshold.

6. The storage apparatus according to claim 5, wherein the controller switches the next second group to the second group already in the active mode after executing processing for diagnosing storage devices constituting a storage resource for the next second group.

7. The storage apparatus according to claim 1, wherein the controller sets some groups from among the plurality of second groups as groups always in the active mode;

and

sets a plurality of groups other than the some groups of the plurality of second groups as groups whose status is switched between the active mode and the power-saving mode.

8. The storage apparatus according to claim 1, wherein the controller changes the number of groups to be set in the active mode at the same time, with respect to the plurality of second groups whose status is switched between the active mode and the power-saving mode, according to the state where they are accessed by the host computer.

9. The storage apparatus according to claim 1, wherein the storage pool has a first pool and a second pool;

the first pool has a first storage resource constituted from a plurality of storage devices that are classified into a first tier;

the second pool has a second storage resource constituted from a plurality of storage devices that are classified into a second tier;

the plurality of storage devices classified into the first tier are classified into a plurality of groups; and

the plurality of storage devices classified into the second tier are classified into a plurality of groups; and

wherein the controller sets all the plurality of groups belonging to the first tier to be capable of switching to the active mode or the power-saving mode; and

sets some groups of the plurality of groups belonging to the second tier to be always in the active mode and sets the remaining groups to be capable of switching to the active mode or the power-saving mode.

10. The storage apparatus according to claim 1, wherein if it is determined that the pool is accessed by the host computer to write new data, the controller allocates the storage area from the storage resource of the group in the active mode, from among the plurality of groups, to the logical volume.

11. The storage apparatus according to claim 10, wherein if it is determined that the pool is accessed by the host computer to write update data, the controller specifies a group having a storage resource to which an object area of the access belongs;

detects a mode for the specified group; and

writes the update data to the storage resource of the group in the active mode if the detected mode is the power-saving mode.

12. The storage apparatus according to claim 11, wherein the controller releases a storage area of the update data in the storage resource of the specified group from allocation to the logical volume;

and prioritizes allocation of the storage area over writing of new data to the storage resource of the specified group.

13. A storage control method for a storage apparatus comprising:

a volume accessed by a host computer;

a pool having a storage resource; and

a controller for controlling allocation of a storage area from the storage resource in response to write access from the host computer to the volume;

wherein the controller classifies a plurality of storage devices that provide the pool with the storage resource, into a plurality of groups;

wherein the controller sets some of the plurality of groups to an active mode in which the storage devices belonging to the some groups are made to enter an activated state;

sets other groups to a power-saving mode in which the storage devices belonging to those other groups are made to enter a power-saving state;

sequentially switches between the group, which is set to the active mode, and the group, which is set to the power-saving mode, from among the plurality of groups; and

allocates the storage area from the storage resource for the group to the volume in response to write access by the host computer while the group is in the active mode.