Patent ID: 7149922
Filing Date: 2006-12-12
Classification: G06F,H04L

Abstract:
1. A storage system comprising a cache memory, plural storage controllers and a storage device, in which said cache memory is connected to said plural storage controllers; said storage controller has a network processor, a file system processor and a disk processor; said network processor has means for making and storing first data for storage to said cache memory from an access request received from an external device, and means for making and transmitting a first request from said access request to said file system processor; said file system processor has means for receiving said first request from said network processor; means for making a second request for getting access to the storage device from said first request, and means for transmitting said second request to said disk processor; said disk processor has means for receiving said second request, and means for controlling data transfer between said cache memory and said storage device in accordance with said second request, wherein, when a failure occurs in a first storage controller, a second storage controller takes over the processing of the first storage controller by using a log area corresponding to the first storage controller, and wherein said cache memory has a log area corresponding to each of said plural storage controllers, and said storage controller stores said first data to said corresponding log area.