STORAGE SYSTEM AND DATA CONTROL METHOD

• US 20180039444A1
• Filed: 04/09/2015
• Published: 02/08/2018
• Est. Priority Date: 04/09/2015
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: YAMAMOTO, Takahiro, FUJIMOTO, Kazuhisa, AKUTSU, Hiroaki
• Granted Patent: US 10,452,302 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 3/0616 in relation to life time, e.g. increasing Mean Time Between Failures [MTBF]
• CPC Class Codes: G06F 3/0647 Migration mechanisms
• CPC Class Codes: G06F 3/0649 Lifecycle management
• 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 3/0688 Non-volatile semiconductor memory arrays

Abstract

A storage system and data control method capable of extending the service lifes of storage devices of the same type and with different properties and reducing operation management cost are proposed. The storage system includes: a first storage device; a second storage device with a smaller upper limit number of writes and a larger storage capacity per unit area than those of the first storage device; and a processor that allocates storage areas from the first storage device and the second storage device to a virtual volume to be provided to a host, wherein the processor relocates data which is stored in a storage area with higher write frequency from the host than a predetermined write threshold, from among the storage areas allocated from the second storage device to the virtual volume, from the storage area of the second storage device to a storage area of the first storage device.

Claims

1. A storage system comprising:

a first storage device;

a second storage device with a smaller upper limit number of writes and a larger storage capacity per unit area than those of the first storage device; and

a processor that allocates storage areas from the first storage device and the second storage device to a virtual volume to be provided to a host,

wherein the processor relocates data which is stored in a storage area with higher write frequency from the host than a predetermined write threshold, from among the storage areas allocated from the second storage device to the virtual volume, from the storage area of the second storage device to a storage area of the first storage device.

2. The storage system according to claim 1,

wherein the processor relocates data which is stored in a storage area with write frequency from the host equal to or lower than the write threshold, from among the storage areas allocated from the first storage device to the virtual volume, from the storage area of the first storage device to a storage area of the second storage device.

3. The storage system according to claim 1,

wherein when a storage area is to be newly allocated from either the first storage device or the second storage device to the virtual volume and the processor predicts write frequency from the host to the newly allocated storage area and the predicted write frequency is equal to or higher than a predetermined new write threshold, the processor newly allocates the storage area from the first storage device.

4. The storage system according to claim 1,

wherein when a storage area is to be newly allocated from either the first storage device or the second storage device to the virtual volume and the processor predicts write frequency from the host to the newly allocated storage area and the predicted write frequency is lower than a predetermined new write threshold, the processor newly allocates the storage area from the second storage device.

5. The storage system according to claim 1,

wherein when a storage area is to be newly allocated from either the first storage device or the second storage device to the virtual volume, the processor newly allocates the storage area from either the first storage device or the second storage device on the basis of a predetermined workload type.

6. The storage system according to claim 1,

wherein the processor calculates the write threshold on the basis of the upper limit number of writes to the first storage device and the upper limit number of writes to the second storage device.

7. The storage system according to claim 1,

wherein the processor reports a recommended capacity of the first storage device and a recommended capacity of the second storage device which are required to maintain service life on the basis of the write frequency from the host and the write threshold.

8. The storage system according to claim 1,

further comprising a third storage device with no limitation to the upper limit number of writes,

wherein the processor:

sets storage areas provided from the first storage device and the second storage device to a first tier and sets storage areas provided from the third storage device to a second tier;

relocates data stored in a storage area with I/O frequency which is a sum of write frequency and read frequency from the host and is equal to or higher than a predetermined inter-tier I/O threshold, from among the storage areas allocated from the second tier to the virtual volume, from a storage area of the second tier to a storage area of the first tier; and

relocates data stored in a storage area with higher write frequency from the host than the write threshold, from among the storage areas allocated from the first tier to the virtual volume and allocated from the second storage device, from a storage area of the second storage device to a storage area of the first storage device.

9. The storage system according to claim 8,

wherein the processor relocates data stored in a storage area with write frequency from the host equal to or lower than the write threshold, from among the storage areas allocated from the first tier to the virtual volume and allocated from the first storage device, from a storage area of the first storage device to a storage area of the second storage device.

10. The storage system according to claim 8,

wherein the processor relocates data stored in a storage area with write frequency from the host equal to or higher than a predetermined write demotion threshold to maintain service life, from among the storage areas allocated from the first tier to the virtual volume, to a storage area of the second tier.

11. A data control method for a storage system including:

a first storage device;

a second storage device with a smaller upper limit number of writes and a larger storage capacity per unit area than those of the first storage device; and

a processor that allocates storage areas from the first storage device and the second storage device to a virtual volume to be provided to a host,

the data control method comprising;

a first step executed by the processor relocating data which is stored in a storage area with higher write frequency from the host than a predetermined write threshold, from among the storage areas allocated from the second storage device to the virtual volume, from the storage area of the second storage device to a storage area of the first storage device;

a second step executed by the processor relocating data which is stored in a storage area with write frequency from the host equal to or lower than the write threshold, from among the storage areas allocated from the first storage device to the virtual volume, from the storage area of the first storage device to a storage area of the second storage device.