Chapter 7. Highly Available controller pairs 79operates at up to 8 Gbps. With a Fabric-attached MetroCluster, the distance between sitescan be expanded from 500 meters up to a maximum of 100 km.Fabric-attached MetroClusters has the following characteristics: Fabric-attached MetroClusters contain two complete, separate copies of the data volumesor file systems that you configured as mirrored volumes or file systems in your HA pair. The fabric-attached MetroCluster nodes can be physically distant from each other beyondthe 500 meter limit of a Stretch MetroCluster. Maximum distance between the fabric-attached MetroCluster nodes is up to 100 km,depending on the switch configuration. A fabric-attached MetroCluster connects the two controllers nodes and the disk shelvesthrough four SAN switches called the Back-end Switches. The Back-end Switches are IBM/Brocade Fibre Channel switches in a dual-fabricconfiguration for redundancy.Figure 7-5 shows a simplified Fabric-attached MetroCluster. Use a single disk shelf per FibreChannel switch port. Up to two shelves are allowed.Figure 7-5 Simplified Fabric-attached MetroClusterSetup requirements and restrictions for fabric-attached MetroClustersYou must follow certain requirements and restrictions when setting up a new fabric-attachedMetroCluster configuration.The setup requirements for a fabric-attached MetroCluster include those for standard andmirrored HA pairs, with the following exceptions.Tip: The back-end Fibre Channel switches can be used for HA node pair and disk shelfpair connectivity only.
