Storage controller and control method thereof

Abstract

A storage controller executes logical format to enable host access to a physical disk, where the logical format of a physical disk is executed without waiting for host access. The storage controller comprises a logical format management module having bit map memory for managing progress information on format processing of a logical volume, and a lower layer module which accesses a physical disk according to the request of the management module. The management module judges whether all the access areas have been formatted referring to the bit map memory, requests the disk access to the lower layer module if judged as formatted, while, issues a logical format processing request before the disk access, queues the disk access request to the queue if not formatted, further searches the unformatted area from the bit map memory, and issues a logical format processing request if no disk access request exists in the queue.