STORAGE SYSTEM AND CONTROL METHOD THEREFOR

• US 20170344313A1
• Filed: 01/23/2015
• Published: 11/30/2017
• Est. Priority Date: 01/23/2015
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: HAYASAKA, Mitsuo, MATSUBARA, Kazumasa, TAKADA, Masanori, YOSHII, Yoshihiro
• Granted Patent: US 10,452,321 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 11/2015 Redundant power supplies power supply failure G06F1/30
• CPC Class Codes: G06F 11/2058 using more than 2 mirrored copies
• CPC Class Codes: G06F 11/2084 on the same storage unit
• 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 3/0653 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 3/08 from or to individual record carriers, e.g. punched card , memory card, integrated circuit [IC] card or smart card

Abstract

A storage system has a cluster structure in which a node is connected with a different node, the node having a volatile memory for storing first update data from a host and a first non-volatile memory for storing second copy data of second update data from the host to the different node, and having a copy management processing unit for storing first copy data of the first update data into a second non-volatile memory of the different node, and a storage service processing unit for transmitting, to the host, a response with respect to an update request of the first update data in response to the storage of the first copy data of the first update data by the copy management processing unit into the second non-volatile memory of the different node.

Claims

1. ] A storage system comprising a node and a different node connected with the node,

wherein the node includes a volatile memory for storing first update data from a host and a first non-volatile memory for storing second copy data of second update data from the host to the different node, and

further includes a copy management processing unit for storing first copy data of the first update data into a second non-volatile memory of the different node, and a storage service processing unit for transmitting, to the host, a response with respect to an update request of the first update data in response to the storage of the first copy data into the second non-volatile memory of the different node.

2. ] The storage system according to claim 1, wherein the copy management processing unit writes out the first update data into a storage device, and deletes the first copy data that is stored in the second non-volatile memory and is corresponding to the written-out first update data in any of the cases where the data amount of the first copy data stored in the second non-volatile memory of the different node exceeds a predefined amount, where a predefined time passes since the first copy data is stored, and where the copy management processing unit receives a compulsory write-out request from the host.

3. ] The storage system according to claim 2, wherein the node performs battery backup on a predefined area of the volatile memory to create a third non-volatile memory in response to the detection of the failure of the different node, and stores the first update data stored in the volatile memory into the third non-volatile memory.

4. ] The storage system according to claim 3, wherein the node includes a redundant processing unit that saves the second copy data stored in the first non-volatile memory and the first update data stored in the third non-volatile memory into a predefined save area of the storage device.

5. ] The storage system according to claim 4, wherein the node retrieves the second copy data into the first non-volatile memory and the first update data into the volatile memory from the save area in response to the recovery from the failure of the different node.

6. ] The storage system according to claim 1, wherein at least one of the first non-volatile memory of the node and the second non-volatile memory of the different node is a battery backed-up volatile memory.

7. ] A control method for a storage system having a cluster structure in which a node and a different node are connected,

wherein the node includes a volatile memory for storing first update data from a host and a first non-volatile memory for storing second copy data of second update data from the host to the different node,

stores first copy data of the first update data into a second non-volatile memory of the different node, and

transmits, to the host, a response with respect to an update request of the first update data in response to the storage of the first copy data into the second non-volatile memory of the different node.

8. ] The control method for the storage system according to claim 7, wherein the node saves the second copy data stored in the first non-volatile memory into a predefined save area of the storage system.

9. ] The control method for the storage system according to claim 8, wherein the node retrieves the second copy data into the first non-volatile memory from the save area in response to the recovery from the failure of the different node.

10. ] The control method for the storage system according to claim 7, wherein at least one of the first non-volatile memory of the node and the second non-volatile memory of the different node is a battery backed-up volatile memory.