Patent ID: 8862812
Filing Date: 2014-10-14
Classification: G06F,H04L

Abstract:
1. A system comprising: a first storage system including a first NAS (Network Attached Storage) module having a first network interface to communicate with a host computer, a first storage unit, a first storage controller to manage first storage volumes on the first storage unit, and a first memory to store a first control program to process an input/output request received by the first storage system; and a second storage system including a second NAS module having a second network interface to communicate with the host computer, a second storage unit, a second storage controller to manage second storage volumes on the second storage unit, and a second memory to store a second control program to process an input/output request received by the second storage system; wherein said first storage system manages first address of said first network interface as effective and second address of said second network interface as standby; wherein the first controller further manages third storage volumes, which are mapped to the second storage volumes provided by the second storage controller, by referring to a table managing said first storage volumes as internal storage volumes and said third storage volumes as external storage volumes; and wherein when said first NAS module detects failure of said second storage system, said first storage controller is configured to mount said third storage volumes which are mapped to the second storage volumes provided by the second storage controller and are managed as external storage volumes in the table, and said first storage controller makes said managed second address effective, so that the host computer can access the second storage volumes via said first storage system.