HP NonStop G-Series - Manual (Page 271)

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.
These three methods are supported for updating to the split-star or tri-star topology:
•
Merging two star topologies to create a split-star topology
•
Merging a star topology with a split-star topology to create a tri-star topology
•
Merging three star topologies to create a tri-star topology
The major steps in updating a topology are:
1. Review the planning information in the ServerNet Cluster Manual for your type of update. Decide which nodes
will be connected to each pair of switches in the new topology by using the planning forms in the manual.
2. Ensure you have all the cluster switches and ServerNet cables in place to expand your cluster. For complete
hardware requirements, see the ServerNet Cluster Manual.
3. Ensure that at least one node is connected to each cluster switch.
4. Ensure you have the minimum levels of software running on all the nodes of your cluster. Because you are using
OSM to perform the update, you might already have newer versions of the software described in the manual.
Even so, be sure all nodes meet the minimum requirements described in
Software Requirements for Split-Star
and Tri-Star Topologies .
5. Ensure that you have the minimum version of firmware and configuration on each cluster switch. See Software
Requirements for Split-Star and Tri-Star Topologies .
CAUTION: Do not proceed if you have the T0569AAA configuration running on any of the switches. Doing so
can cause outages on every system in the cluster.
6. Use the OSM service connection to ensure that the clusters to be merged are trouble free. If there are any
alarms, follow the repair actions to resolve the problems.
7. Use the Configuration Update action to change the configuration tags so they are compatible with the new
topology:
•
If you are merging two star topologies to create a split-star topology, change the configuration tags for the
switches in one star topology to support node numbers 9 through 16.
•
If you are merging a split-star topology with a star topology to create a tri-star topology, change the
configuration tags for the switches in the star topology to support node numbers 17 through 24. This practice
avoids the need for a configuration tag change on the split-star topology. (The split-star topology already
uses node numbers 1 through 16.)
•
If you are merging three star topologies to create a tri-star topology, change the configuration tags for the
switches in one star topology to support node numbers 9 through 16. Change the configuration tags for
the switches in another star topology to support node numbers 17 through 24. (The remaining star topology
should already use node numbers 1 through 8.)
NOTE: Changing the configuration tag requires a hard reset of the switches, resulting in a temporary disruption
of ServerNet connectivity. After the configuration tags match on respective X and Y switches, the connectivity
is repaired.
8. Perform the Update Topology action on each cluster. When prompted, click the Disable Cluster Alarms button.
No alarms related to connectivity (that would otherwise be dialed out on multiple nodes) are dialed out for two
hours unless you perform the Rediscover action. Other types of alarms, such as hardware failures, are still dialed
out.
9. Disconnect any existing X-fabric cables between the cluster switches. (If you are updating from a star topology,
there are no existing cables between switches.)
10. Connect all the cables between the X-fabric switches to support the new topology. The new switch port connections
will differ from the original cluster. See
Cable Connections Between Star Groups . For more information on
connecting cables refer to the ServerNet Cluster Manual.
11. Use OSM to monitor the connectivity on the X fabric for all the nodes and switches. Connectivity on the X fabric
should be restored over time. Confirm that the original nodes of the cluster are visible. If necessary, resolve any
connectivity problems by following the repair actions.
12. Disconnect any existing Y-fabric cables between the cluster switches. (If you are updating from a star topology,
there are no existing cables between switches.)
13. Connect all the cables between the Y-fabric switches to support the new topology. The new switch port connections
will differ from the original cluster. See
Cable Connections Between Star Groups . For more information on
connecting cables, refer to the ServerNet Cluster Manual.
Updating Star Topologies 271