A storage system includes a plurality of kinds of packages as each channel adapter, cache switches, disk adapters, basic memory boards, a shared memory, cache memories, memory board expansions and individual disk drives. Nonvolatile memories are mounted on each of those packages to store event information concerning the package on which the respective memory is mounted. In case a package is exchanged or newly installed or in case a package fails, the event information is stored in the nonvolatile memory of the package in correspondence with the packaging position information of the package in the storage system, so that this event information can be accessed at any time.