ServerNet Cluster 6770 Hardware Installation and Support Guide

Connecting the ServerNet Fiber-Optic Cables
ServerNet Cluster 6770 Hardware Installation and Support Guide—522544-002
6-3
Routing and Connecting the Cables
Routing and Connecting the Cables
1. From the service side, route the fiber-optic ServerNet cables through the enclosure
or rack toward the ServerNet ports.
2. For each node, connect one fiber-optic ServerNet cable to one of the ports
numbered 0 through 7 on the ServerNet II Switch on the X fabric.
Note. Do not connect the other end of the fiber-optic cables from the ports on a ServerNet
II Switch until instructed to do so by one of the procedures indicated in the table.
Table 6-1. Connecting the Cables
Connecting
From
ServerNet II
Switch
Ports... To... Procedure Notes
0 through 7 MSEB on a
node
Configure
ServerNet node
(TSM)
Add Node to
ServerNet
Cluster action of
System resource
(OSM)
If you connect a cable from one of
these ports to a node before you
are instructed to do so, the guided
procedure cannot automatically
generate Expand-over-ServerNet
line-handler processes for that
node. For more information about
the automatic configuration of
line-handler processes, see the
online help for this guided
procedure.
8 through 11 Another switch
on the external
same fabric
Add Switch
(TSM)
Update Topology
action of the
ServerNet
Cluster resource
(OSM)
For ServerNet clusters that have
only one switch per fabric, the Add
Switch procedure or Update
Topology action is not necessary. In
that case, these ports are unused.
Caution. Do not connect the four-lane link until you are instructed to do so by the procedure
for adding a cluster switch. Connecting the four-lane link between two ServerNet II switches
running the T0569AAA configuration can cause an outage on every node in the cluster if the
NNA version is 5. (FCO 39746B replaced Version 5 NNAs with NNA version 22.) Power cycling
each node might be necessary to recover from this outage.
Outages can occur because the cluster is unprotected by the neighbor-checking logic if
ServerNet II switches running T0569AAA configuration are connected. Connecting two
ServerNet II switches running T0569AAA configuration can create an invalidly configured split-
star topology in which ServerNet packets sent by nodes 1 through 8 to nodes 9 through 16 loop
indefinitely between the two cluster switches.