Patent ID: 8880939
Filing Date: 2014-11-04
Classification: G06F

Abstract:
1. A storage subsystem coupled to a host computer comprising: a storage device unit for storing data from the host computer; a control unit for controlling a storage area of the storage device; and a memory unit accessed by the control unit; wherein a logical device in the storage device unit is allocated to a virtual logical device provided to the host computer and a user data from the host computer is stored in the logical device of the storage device unit using a page mapping information stored in the memory unit and a track mapping information stored in the storage device unit; the track mapping information is composed of a first track information including a status information and an address information within the logical device and a second track information including a status information and an address information within the virtual logical device; the first track information and the second track information are associated via the address information; and when the first track information or the second track information is abnormal, recovery is performed using an address information in the other track information which is normal.