Abstract

Methods and associated structure for updating and propagating firmware updates in a multiple redundant controller storage subsystem. The methods of the present invention assure that the storage subsystem remains operable processing host system I/O requests while the redundant controllers manage the firmware update process. At least one controller of a plurality of redundant controllers in the system remains available for processing of host I/O requests as the controllers manage the firmware update process. A management client process operable on an administrative system coupled to the first of the redundant storage controllers transfers a structured firmware file to the first redundant controller. The management client need perform no further management of the update process. Rather, the controller themselves manage the process in accordance with metadata stored within the firmware file along with the programmed instructions to be updated. The first controller and second controller then coordinate and sequence the update process to update both controllers with a compatible, consistent version of firmware. During the update process, one of the two redundant controllers remains operable and assumes ownership of all storage volumes in the subsystem to enable continued operation of host system I/O requests during the firmware update process. In this manner the storage system in accordance with the present invention provides a seamless firmware update process that is robust, seamless and imposes minimal management responsibility on a management client process.