US 2010/0306575 A1Published application

Path changeover support device and method

AssigneeHitachi, Ltd.

InventorNaoki Futawatari

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Abstract

Port management information is prepared for managing information related to the status of each of a plurality of ports possessed by a storage system in a unified manner. Change of the status related to any one of a plurality of ports from “normal” to anomalous is detected. For a subject external device which is using the anomalous path as an I/O path, a “normal” port is selected, on the basis of the port management information, from one or more ports related to one or more paths which are being used as alternate paths. And information related to this “normal” port which has been selected is notified to the subject external device. During path changeover, the subject external device selects as an I/O path an alternate path which is related to the “normal” port specified from the notified information.

Claims15

Dependent claims

In a system in which a plurality of paths extend between a plurality of ports possessed by a storage system and an external device, said plurality of paths including a path which is being used as an I/O path and one or more paths which are being used as alternate paths, and with the path which is being used as an I/O path being a path which is used when said external device issues an I/O command, and the path which is used as an alternate path being capable of being used as an I/O path:

a path changeover support device, comprising:
a storage resource which stores port management information including information related to a status for each of a plurality of ports possessed by the storage system;
a status detection unit which detects change from “normal” to anomalous of the status of any one of said plurality of ports;
a port selection unit which, for a subject external device, being an external device which is using the anomalous path, being the path related to the anomaly, as an I/O path, on the basis of said port management information, selects a “normal” port, being a port whose status is “normal”, from among one or more ports related to one or more paths which are being used as alternate paths;
and
a port notification unit which notifies to said subject external device information which is related to the selected “normal” port related to an I/O path instead of the anomalous path.

3 more elements

A storage system, comprising:

a controller possessing a plurality of ports;
a storage resource which stores port management information including information related to a status of each of said plurality of ports;
and
a plurality of physical storage devices which are based upon a plurality of logical storage devices;
wherein a plurality of paths extend between said plurality of and external devices, said plurality of paths including a path which is being used as an I/O path and one or more paths which are being used as alternate paths, and with the path which is being used as an I/O path being a path which is used when an external device issues an I/O command, and the path which is used as an alternate path being capable of being used as an I/O path;
wherein said port management information includes;
port status information which specifies which ports have what status;
I/O path number information, being information which specifies how many I/O paths are related to which ports;
external device information which specifies which external device is using which path related to which port as an I/O path, and which path related to which port as an alternate path;
and
path fault information, being information which specifies upon which path a path fault is occurring;
said faulty path being a path which has become impossible to use due to some reason other than a port fault;
and wherein said controller:
(15-1) detects, as the status of any one of said plurality of ports, change from “normal” to anomalous;
and
(15-2-A) if it has been detected that a port fault has occurred upon any one of the ports, among two or more subject external devices which are using an anomalous path related to said port fault as an I/O path, executes (A-1) and (A-2) below in relation to said subject external devices, in order from that subject external device for which the total number of paths is the least:
(A-1) selection, on the basis of said port management information, of a “normal” port from one or more ports related to one or more paths which are being used as alternate paths;
and
(A-2) updating of said port management information, and execution of (A11) through (A13) below with said updated port management information:
(A11) specifying an alternate path related to the port selected by (A-1) above to become an I/O path;
(A12) increasing the number of I/O paths for said port selected in (A-1) above;
and
(A13) reducing the number of I/O paths for said port upon which a port fault is occurring;
(15-2-B) if it has been detected that a path fault has occurred upon any one of the paths, updates said path fault information within said port management information to information which specifies that a path fault is occurring upon said path, and executes the processing described in (B-1) and (B-2) below in relation to the subject external device which is using the anomalous path related to the path fault as an I/O path:
(B-1) selection, on the basis of said port management information, of a “normal” port from one or more ports related to one or more paths which are being used as alternate paths;
and
(B-2) updating of said port management information, and execution of (B11) through (B13) below with said updated port management information:
(B11) specifying an alternate path related to the port selected in (B-1) above to become an I/O path;
(B12) increasing the number of I/O paths for said port selected in (B-1) above;
and
(B13) reducing the number of I/O paths for the port related to the anomalous path upon which a path fault is occurring;
(15-2-C) and, if it has been detected that the status of any one of the ports has become “maintenance”, among two or more subject external devices which are using an I/O path related to the anomalous port related to “maintenance”, executes (C-1) and (C-2) below in relation to said subject external devices, in order from that subject external device for which the total number of paths is the least:
(C-1) selection, on the basis of said port management information, of a “normal” port from one or more ports related to one or more paths which are being used as alternate paths;
and
(C-2) updating of said port management information, and execution of (C11) through (C13) below with said updated port management information:
(C11) specifying the alternate path which is related to the port selected in (C-1) above to become an I/O path;
(C12) increasing the number of I/O paths for said port selected in (C-1) above;
and
(C13) reducing the number of I/O paths for said port related to “maintenance”;
wherein said total number of paths is calculated as the total number of I/O paths and alternate paths.

37 more elements

Dependencies are inferred from the claim text.