METHOD FOR DISPLAYING PAIR STATE OF COPY PAIRS

A method for displaying a state of a copy pair which is a pair of logical volumes belonging to one or a plurality of storage sub systems connected to a task server, including: monitoring periodically, by a backup management program on the task sever, an operation condition of an application on the task server; notifying, by the backup management program, a maintenance to a control program on the storage sub system, if the application is on a stop condition at some time; setting, by the control program which receives the notification, "on-maintenance" to an action mode on the storage sub system; after a maintenance by a user and at time of a restart of the application, checking, by the backup management program, the operation condition of the application and notifying a release of the maintenance to the control program; and setting, by the control program which receives the notification of the release, the action mode of the storage sub system to a normal condition.