Configuring I/O modules

Use the Chassis Management Module web interface to configure ports and IP addresses for the I/O modules in the Flex System Carrier-Grade chassis.

You must enable at least one external port on an Ethernet switch module in I/O module bay 1 or 2 to communicate with the Ethernet controllers that are integrated in each compute node. See the documentation that comes with the I/O module for information about configuration. I/O module information is available at the Flex System network devices information page.

Note: If a pass-thru module is installed in I/O module bay 1, you must configure the network switch that the pass-thru module is connected to. See the documentation that comes with the network switch for more information.

To determine which I/O modules are compatible with the Flex System Carrier-Grade chassis, see the Lenovo ServerProven website.

Port mapping

Table 1 summarizes the Flex System Carrier-Grade chassis I/O bay and port interconnections for each network switch and adapter. In this table, the bay numbers correspond to the I/O bay in the chassis. Installing a second network switch in the chassis enables a redundant path and a separate connection from the compute node (or other device) to the external devices on the network. The second switch port connection in Table 1 allows for dual paths from the compute node (or other device) to external devices.

Table 1. I/O bay to expansion adapter port mapping
Chassis I/O bay Compute node I/O expansion adapter port
1 Port 0 connection on the I/O expansion adapter in compute node position 1
2 Port 1 connection on the I/O expansion adapter in compute node position 1
3 Port 0 connection on the I/O expansion adapter in compute node position 2
4 Port 1 connection on the I/O expansion adapter in compute node position 2

The node in bay 1 in Figure 1 shows that when a compute node is shipped with a LAN on motherboard (LOM) connector, the LOM connector provides the link from the node system board to the chassis midplane. If required, the LOM connector can be removed from the compute node and an I/O expansion adapter can be installed in the node. A compute node with an I/O expansion adapter installed is shown in bay 2 in Figure 1.

Figure 1. LOM, I/O adapter, and network switch connections

A total of two I/O expansion adapters (M1 and M2 in Figure 2) can be installed in a 1-bay compute node. Up to four I/O expansion adapters can be installed in a 2-bay compute node.

Each I/O expansion adapter has two connectors, one connects to the node system board and the second connector is a high-speed interface that connects to the midplane when the node is installed in the chassis.

As shown in Figure 2, each of the links to the chassis midplane (shown in blue) are four links wide. The exact number of links used on each I/O expansion adapter is dependent on the type of application-specific integrated circuit (ASIC) that is installed and the number of ports that are wired.

Figure 2. Logical layout of node-to-switch interconnections