Command multiplex number monitoring control scheme and computer system using the command multiplex number monitoring control scheme

摘要

There is provided a command multiplex number monitoring control scheme capable of avoiding issue of a QF status and getting rid of system performance degradation without adding command processing resources. Command issue multiplex numbers CMs (32, 16 and 8) for WWN1-LU2, WWN2-LU1 and WWN3-LU0 are set in a port PT1 so as to be associated with the host bus adaptors HBAs in higher rank apparatuses HOST-1, HOST-2 and HOST-3. Denoting the sum total of command issue multiplex numbers CMs for respective set access permissions by (C), an access permission satisfying the relationship represented as “command processing multiplex limit number (B)≧the sum total (C) of command issue multiplex numbers CMs for respective access permissions” is not permitted. Thus, the command issue multiplex numbers of the connected higher rank apparatuses are monitored.