6.3 Examples of topology table

The following examples show various network configurations and what their topology tables would look like when the topology table is displayed in the CF Wizard on a totally unconfigured cluster. For simplicity, the check boxes are omitted.

Example 1

In this example, there is a three-node cluster with three full interconnects.

Figure 6.1 A three-node cluster with three full interconnects

The resulting topology table for the above figure is shown in the following table.

Table 6.2 Topology table for 3 full interconnects
FUJI	Full interconnects
	Int 1	Int 2	Int 3
fuji2	eth0	eth1	eth2
fuji3	eth0	eth1	eth2
fuji4	eth0	eth1	eth2

Since there are no partial interconnects or unconnected devices, those columns are omitted from the topology table.

Example 2

In this example, fuji2's Ethernet connection for eth1 has been broken.

Figure 6.2 Broken ethernet connection for eth1 on fuji2

The resulting topology table for Figure 63 is shown in Table 7.

Table 6.3 Topology table with broken Ethernet connection
FUJI	Full interconnects		Partial interconnects	Unconnected devices
	Int 1	Int 2	Int 3
fuji2	eth0	eth2	missing	eth1
fuji3	eth0	eth2	eth1
fuji4	eth0	eth2	eth1

In the table "Table 6.3 Topology table with broken Ethernet connection," eth1 for fuji2 now shows up as an unconnected device. Since one of the interconnects is missing a device for fuji2, the Partial Interconnect column now shows up. Note that the relationship between interconnect numbering and the devices has changed between the table "Table 6.2 Topology table for 3 full interconnects" and the table "Table 6.3 Topology table with broken Ethernet connection". In Table, for example, all eth1 devices were on Int 2. In the table "Table 6.3 Topology table with broken Ethernet connection," the eth1 devices for Nodes B and C are now on the partial interconnect Int 3. This change in numbering illustrates the fact that the numbers have no real significance beyond the topology.

Example 3

This example shows a cluster with severe networking or cabling problems in which no full interconnects are found.

Figure 6.3 Cluster with no full interconnects

The resulting topology table for the above figure is shown in the blow table.

Table 6.4 Topology table with no full interconnects
FUJI	Partial interconnects		Unconnected devices
	Int 1	Int 2	Int 3
fuji2	eth0	missing	eth2	eth1
fuji3	missing	eth1	eth2	eth0
fuji4	eth0	eth1	missing	eth2

In this table, the full interconnects column is omitted since there are none. Note that if this configuration were present in the CF Wizard, the wizard would not allow you to do configuration. The wizard requires that at least one full interconnect must be present.