Storage system and control software deployment method

A control software deployment method of deploying, in a storage system including a plurality of storage nodes each equipped with one or more storage devices which respectively provide a storage area, one or more control software which read/write requested data from/into a corresponding storage device according to a request from a higher-level device, and a management unit that manages each of the one or more control software in a cluster configured from the plurality of storage nodes, wherein each of the one or more control software retains predetermined configuration information required for reading/writing requested data from/into the corresponding storage device according to a request from the higher-level device, and wherein the one or more control software deployment method comprises the steps of:

• managing a plurality of the one or more control software as a redundancy group, and synchronously updating the predetermined configuration information retained in each of the one or more control software belonging to a same redundancy group;
• retaining control software management information that stores a status of the one or more control software, a redundancy group to which the one or more control software belongs, and volumes of which the redundancy group is in charge;
• when the management unit receives a request from the higher-level device, identifying, by the management unit, a storage node, in which the one or more control software for a redundancy group in charge of a volume related to the request is deployed, on a basis of the control software management information and transferring, by the management unit, the request from the higher-level device to the identified storage node;
• and when a storage node is added to the storage system, migrating, by the management unit, the one or more control software which is running on an existing storage node to the added storage node, configuring, by the management unit, a new redundancy group which has a plurality of control software, and deploying, by the management unit, the plurality of control software of the new redundancy group a plurality of storage nodes including the added storage node.