Storage system and management method of its storage medium

摘要

High availability is provided in a storage system that offers expandability more inexpensively. Provided is a storage system including multiple expanders to be connected to multiple storage mediums, multiple cascades connected respectively to a prescribed number of expanders among the multiple expanders, and multiple control units for respectively controlling the multiple cascades. One end of the multiple cascades is connected with an inter-cascade link, and the inter-cascade link has a logically connected state and a logically disconnected state.