The Server Units are connected to state-of-the-art storage systems via Fibre Channel. Here the storage systems are generally not connected directly to a Server Unit’s Fibre Channel Adapter but via a switch. Such an FC switch at the same time permits multiple connections between the devices which are connected at its ports. Other switches can, in turn, be connected to an FC switch via special ports. A network formed from one or more FC switches is called a fabric. A network of several storage systems which are connected with FC switches is referred to as a Storage Area Network (SAN).
From the BS2000 viewpoint, the FC switches are transparent. BS2000 uses the controllers and devices which are connected via Fibre Channel without having information on the connections in the fabric.
When problems are encountered in attaching devices or faults occur in ongoing operation, it is often difficult to detect the reason for these. An INOP or NINT message of the device error recovery can be caused by connection problems at any point in the SAN. Possibly a device cannot be attached at all because the paths or WWPNs (World Wide Port Number) generated in BS2000 do not exist physically or because the connections generated between the channel and controller are not permitted in the switches.
FC networks in SE Manager
The FC fabrics and connection paths through the fabrics are also displayed in the SE Manager under "Hardware" > "FC networks". Detailed information on this is provided in the “Operation and Administration” manual [57].
These information provides support for:
Detection of generation errors (SUs /390)
- Detection of connection errors between Server and Storage
Location of error states in the SAN