IBM

Apply the following configuration details for Fibre Channel (FC) switches to ensure that you have a valid configuration.

For Fibre Channel connections, the node canisters must be connected to either SAN switches or directly connected to a host port. If the system contains more than one control enclosure, a minimum of two Fibre Channel ports from each node canister must be connected to the SAN.

This configuration provides connections to each of the counterpart SANs that are in the redundant fabric. When iSCSI hosts are attached to node canisters, Ethernet switches must be used.

All back-end storage systems must always be connected to SAN switches only. Multiple connections are permitted from redundant storage systems to improve data bandwidth performance. A connection between each redundant storage system and each counterpart SAN is not required.

For example, in an IBM® DS4000® configuration that contains two redundant storage systems, only two storage system minihubs are usually used. Storage system A is connected to counterpart SAN A, and storage system B is connected to counterpart SAN B. Any configuration that uses a direct physical connection between the node and the storage system is not supported.

When you attach a node to a SAN fabric that contains core directors and edge switches, connect the node ports to the core directors. Then, connect the host ports to the edge switches. In this type of fabric, the next priority for connection to the core directors is the storage systems, leaving the host ports connected to the edge switches.

A SAN must follow all switch manufacturer configuration rules, which might place restrictions on the configuration. Any configuration that does not follow switch manufacturer configuration rules is not supported.