1. Field of the Invention
The present invention relates to a method, system, program, and data structures for testing a network system including input/output (I/O) devices.
2. Description of the Related Art
A storage area network (SAN) comprises a network linking one or more servers to one or more storage systems. Each storage system could comprise a Redundant Array of Independent Disks (RAID) array, tape backup, tape library, CD-ROM library, or JBOD (Just a Bunch of Disks) components. Storage area networks (SAN) typically use the Fibre Channel Arbitrated Loop (FC-AL) protocol, which uses optical fibers to connect devices and provide high bandwidth communication between the devices. In Fibre Channel terms the switch connecting the devices is called a “fabric”. The link is the two unidirectional fibers, which may comprise an optical wire, transmitting to opposite directions with their associated transmitter and receiver. Each fibre is attached to a transmitter of a port at one end and a receiver of another port at the other end. When a fabric is present in the configuration, the fibre may attach to a node port (N_Port) and to a port of the Fabric (F_Port).
Because a Fibre Channel storage area network (SAN) is an amalgamation of numerous hosts, workstations, and storage devices, troubleshooting for errors can often be a somewhat complex process. Currently, in the prior art, a technician will perform a series of tests from a host system in the SAN and test various channels and connections to the storage devices to detect problems and then try to locate the specific source of a problem. Technicians generally rely on their own knowledge, experience and expertise when diagnosing the SAN system for errors. Such knowledge is not a shared resource, but rather an individual point of view and an accumulation of guess work and personal experience. As a result, it is unlikely that different storage experts troubleshoot a storage system in the same manner, thereby leading to possible incorrect or inconsistent diagnosis as well as an increase in the Mean Time To Diagnose (MTTD). Moreover, as the number of SAN systems proliferate, it may become more and more difficult for system administrators to locate available diagnosticians.
Certain “cookbook” approaches to testing a Fibre Channel network have been proposed, such as the “Fibre Channel FC-AL-2 Parametric Test Suite Rev. 7.0”, published by the Fibre Channel Consortium, document no. ANSI X3.272-199X (January 2000), which publication is incorporated herein by reference in its entirety. Such documents describe specific tests that may be performed to troubleshoot a Fibre Channel network. However, again the order in which the tests are selected and performed is still a matter of choice for the diagnostician performing the troubleshooting operations.
Notwithstanding current efforts at troubleshooting network components, such as a SAN, the current art lacks tools that provide an integrated and consistent approach toward diagnostic testing of a SAN and its components.