HP Tc4100 hp mc/serviceguard for Linux configuration guide for HP Netservers - Page 19

Figure 1 Recommended Configuration with Three Data Centers Clients connections Network Switch Channel QS Bonding Network Switch Clients connections DWDM DWDM Third Site DWDM Clients connections Dedicated Heartbeat link Network Switch Network Switch Node A Node B Network Switch Cluster Heartbeat, Client network, CA connections DWDM Dedicated Clients Heartbeat connections link Network Switch Network Switch DWDM Network Switch DWDM Node C Node D FC Hub/Switch FC Hub/Switch Redundant DWDM Links, routed differently FC Hub/Switch FC Hub/Switch XP Disk Array Primary Data Center 1 Primary Data Center 2 XP Disk Array Maximum distance 100 kilometers In the example above, the DWDM boxes connected between the two Primary Data Centers are configured with multiple dark fibre links. The DWDM links are used for both networking and CA data replication. If the DWDM box is fault tolerant, only one is required in each data center. If it's not fault tolerant, two are required in each data center. The Quorum Server site distance can be up to 100 kilometers away from either Primary Data Center since DWDM links are also used. It is also supported to connect to the Arbtitrator data center without DWDM links, as long as the distance is within the allowed specifications for the network type being used.