Patent ID: 7398330

Claim:
A command multiplex number monitoring control scheme in a computer system, the computer system including a storage apparatus and one or more higher rank apparatuses, the storage apparatus including a volume and a storage control apparatus, the volume including one or more logical units, the storage control apparatus including one or more ports, each of the higher rank apparatuses having a world wide name, the higher rank apparatuses being connected to the storage apparatus via a network, comprising: setting command issue multiplex numbers respectively in the higher rank apparatuses for each access permission information constituted of world wide names of the higher rank apparatuses, each of the higher rank apparatuses issuing commends no more than a respective command issue multiplex number; setting the logical units corresponding to the world wide names in the storage apparatus in the ports in the storage apparatus; setting access permission information which defines a situation as abnormal and to-be-rejected when a total of the set command issue multiplex numbers of the higher rank apparatuses exceeds a command processing multiplex limit number of the storage control apparatus; providing in the higher rank apparatuses a reference instruction whereby the command issue multiplex numbers set in the storage control apparatus are referenced from the higher rank apparatuses; setting in the storage control apparatus the command issue multiplex numbers of the higher rank apparatuses managed; wherein for each access path, setting a command processing priority multiplex number that determines priority of command processing in the storage control apparatus for each world wide name provided for each higher rank apparatus and a corresponding logical unit in the storage apparatus, and if a command full status is reported against a command received from one of said higher rank apparatus via a pertinent access path, calculating a multiplex number corresponding to the priority based upon the command processing priority multiplex number for the pertinent access path; comparing the calculated multiplex number corresponding to the priority of the pertinent access path with a command issue multiplex number under processing via the pertinent access path.