Users Guide

Managing I/O Fabric

The chassis can have up to six I/O modules (IOMs), where each IOM is a pass-through or switch module.

The IOMs are classified into three groups—A, B, and C. Each group has two slots—Slot 1 and Slot 2.

The slots are designated with letters, from left to right, across the back of the chassis: A1 | B1 | C1 | C2 |

B2 | A2. Each server has slots for two mezzanine cards (MCs) to connect to the IOMs. The MC and the

corresponding IOM must have the same fabric.

Chassis IO is segregated into three discrete data paths: A, B and C. These paths are described as FABRICS

and support Ethernet, Fibre Channel, or InfiniBand. These discrete fabric paths are split into two IO Banks,

bank one and bank two. Each server IO adapter (Mezzanine Card or LOM) can have either two or four

ports depending on the capability. These ports are divided evenly to IOM banks one and two to allow for

redundancy. When you deploy the Ethernet, iSCSI, or FibreChannel networks, span their redundant links

across banks one and two for maximum availability. The discrete IOM is identified with the fabric identifier

and the bank number.

Example: A1 denotes Fabric A in bank 1. C2 denotes Fabric Cin bank 2.

The chassis supports three fabric or protocol types. The IOMs and Mezzanine Cards in a group must have

the same or compatible fabric types.

• Group A IOMS are always connected to the servers' on-board Ethernet adapters; the fabric type of

Group A is always Ethernet.

• For Group B, the IOM slots are permanently connected to the first MC slot in each server module.

• For Group C, the IOM slots are permanently connected to the second MC in each server module.

NOTE: In the CMC CLI, IOMs are referred to by the convention, switch-n: A1=switch-1,

A2=switch-2, B1=switch-3, B2=switch-4, C1=switch-5, and C2= switch-6.