Storage system and storage controller

• US 20050071559A1
• Filed: 02/03/2004
• Published: 03/31/2005
• Est. Priority Date: 09/29/2003
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Nakayama, Shinichi, Uchiumi, Katsuhiro, Tamura, Keishi
• Granted Patent: US 7,441,095 B2
• Time in Patent Office: Days
• US Class Current: 711/117
• 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 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• CPC Class Codes: G06F 3/0664 at device level, e.g. emulation of a storage device or system
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]

Abstract

Memory resources are effectively utilized by visually setting an external memory resource as an internal memory resource. A first storage controller has a multilayer memory hierarchy constructed by LDEV (logical device) connected from LUN, and VDEV (virtual device) connected to the lower order of the LDEV. At least one of the VDEVs is constructed by mapping the memory resources arranged in external storage controllers. The functions of a stripe, RAID, etc. can be added in the mapping. Various kinds of functions (remote copy, variable volume function, etc.) applicable to the normal internal volume can be also used in a virtual internal volume by using the external memory resource as the virtual internal memory resource so that the degree of freedom of utilization is raised.

Claims

1. A storage system constructed by communicably connecting a first storage controller and a second storage controller and performing data processing according to a request from a host device,

wherein said first storage controller has at least one or more logical units accessed by said host device, and at least one or more intermediate memory hierarchies arranged so as to connect this logical unit and at least one or more memory devices, and

at least one of said intermediate memory hierarchies is connected to a memory device arranged in said second storage controller.

2. A memory control device communicably connected to a host device and a second storage controller and performing data processing according to a request from said host device, and comprising:

at least one or more logical units accessed by said host device; and

at least one or more intermediate memory hierarchies arranged so as to connect said logical unit and at least one or more memory devices;

wherein at least one of said intermediate memory hierarchies is connected to the memory device arranged in said second storage controller.

3. The memory control device according to claim 2, wherein said intermediate memory hierarchy is constructed by arranging at least one or more first memory hierarchies set on said memory device, and at least one or more second memory hierarchies set on this first memory hierarchy, and the memory device arranged in said second storage controller is mapped to said first memory hierarchy.

4. The memory control device according to claim 2, wherein the memory control device further comprises plural logical units able to be accessed from said host device through plural paths different from each other, and

each of said logical units is connected to each of said intermediate memory hierarchies.

5. The memory control device according to claim 2, wherein the memory control device further comprises path information obtaining means for obtaining path information to said memory device arranged in said second storage controller, and

said each path information is recognized as path information to the same memory device when said obtained path information exists in the plural.

6. A control method of a memory control device communicably connected to a host device and a second storage controller and performing data processing according to a request from said host device, and including:

a step for obtaining path information to a memory device arranged in said second storage controller; and

a step for mapping said obtained path information to an intermediate memory hierarchy connected to a logical unit accessed by said host device.

7. A computer program for setting a memory device arranged in a second storage controller to a memory control device as an internal volume, and making the computer execute:

a step for obtaining path information to the memory device arranged in said second storage controller; and

a step for mapping said obtained path information to an intermediate memory hierarchy connected to a logical unit accessed by said host device.

8. A verifying method for verifying an alternating path structure in a memory control device for providing an external memory device arranged in an external storage controller to a host device as if the external memory device is an internal memory device personally arranged, and comprising:

a step for selecting plural paths connected to said external memory device;

a step for reading data from said external memory device through each of these selected paths; and

a step for judging whether each of these read data is conformed or not.

9. A verifying method for verifying an alternating path structure in a memory control device for providing an external memory device arranged in an external storage controller to a host device as if the external memory device is an internal memory device personally arranged, and comprising:

a step for selecting plural paths connected to said external memory device;

a step for reading data from said external memory device through each of these selected paths;

a step for judging whether each of these read data is conformed or not;

a step for writing separate data different from said read data from one of said selected paths when each of the read data is conformed;

a step for again reading data from said external memory device through each of said selected paths; and

a step for judging whether these read data are conformed to said separate data or not.