NonStop S-Series Server Description Manual (G06.24+)

Introduction

HP NonStop S-Series Server Description Manual—520331-003

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Star Topology

The star topology, introduced with the G06.09 RVU, supports up to eight nodes and

requires two 6770 cluster switches—one for the external X fabric and one for the

external Y fabric.

Figure 1-21 shows both fabrics of an eight-node ServerNet cluster connected in a star

topology. As explained previously, each node icon represents a complete

multiprocessor server.

ServerNet cables provide ServerNet links between routing devices. In a ServerNet

cluster, single-mode fiber-optic (SMF) cables link each node to a cluster switch. The

cables are available in 10-meter, 40-meter, and 80-meter lengths. An 80-meter

plenum-rated cable is available.

Two ServerNet cables are needed for each node. One cable connects the MSEB in

slot 51 of group 01 to the cluster switch serving the X fabric. The other cable connects

the MSEB in slot 52 of group 01 to the cluster switch serving the Y fabric.

Note. You can configure a single system so that the software necessary for external ServerNet

communication is running and ready to communicate with other nodes. However, if no other

nodes are connected to the cluster switches, no communication occurs. In this case,

communication with remote nodes occurs as soon as the nodes are configured and connected.

Note. Only MSEBs (modular ServerNet expansion boards), not SEBs, are suitable for

connecting external fabrics.