User guide

Migrating to the Layered Topology describes how to migrate a cluster from one of the
star topologies to the layered topology.
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Adding Zones or Layers to a Layered Topology describes how to add zones or layers to a
cluster already using the layered topology.
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Updating Star Topologies describes how to use the OSM Update ServerNet Cluster
Topology action to:
Merge two star topologies to create a split-star topology❍
Merge a star topology and a split-star topology to create a tri-star topology❍
Merge three star topologies to create a tri-star topology❍
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Migrating to the Layered Topology
The layered topology requires HP NonStop ServerNet Switches (model 6780).
To migrate a ServerNet cluster from one of the star topologies to the layered topology, you
must have on hand enough 6780 switches and ServerNet cables to support your cluster. You
need at least two switches (one for each external fabric) for every eight nodes.
For details on planning a migration to the layered topology, including hardware, software, and
cabling requirements, see the ServerNet Cluster 6780 Planning and Installation Guide.
For a quick reference on cable connections, see Cable Connections in a Layered Topology.
Adding Layers or Zones to a Layered Topology
You can expand an existing ServerNet cluster that uses the layered topology by adding layers or
zones.
For complete instructions for adding layers or zones, see the ServerNet Cluster 6780 Planning
and Installation Guide.
Updating Star Topologies
Follow this procedure only if you plan to use OSM to merge clusters to create a split-star or
tri-star topology.
Note: Do not use this procedure unless you have the OSM package running on all nodes of
the cluster. Instead, use the TSM Add Switch guided procedure as described in the
ServerNet Cluster Manual to perform the update. If you use the TSM Add Switch
procedure, and the OSM package is running on any nodes in the cluster, be sure the
OSM Notification Director is not configured to dial out alarms.