Patent ID: 7380054

Claim:
A storage system comprising: a plurality of different kinds of exchangeable functional parts for storing data for use by a host device, wherein said functional parts are packages which perform different functions of said storage system, wherein each package can be decoupled from said storage system and exchanged with a new package which can then be coupled to said storage system; wherein said packages include: channel adapter packages which function to communicate data with said host device, cache memory packages which function to temporarily store data that is transferred from said channel adapter packages, disk adapter packages having a control function to store data stored in said cache memory packages in a plurality of disk drives; switch packages which function to transfer data mutually among said channel adapter packages, said cache memory packages and said disk adapter packages, and a shared memory package in which control information is written concerning control of said storage system including said channel adapter, said disk adapter, said cache memory and said switch packages; wherein each of said packages includes memory means; wherein each of said memory means stores event information which is configured so as to exhibit a correspondence between an event which has occurred during operation of a package which includes said memory means and packaging position information which describes a location of said package, which includes said memory means, in said storage system; and wherein said event information stored in said memory means of each package is accessible by a user to determine a status of a particular package independent of the other packages.