Using Serviceguard Extension for RAC, 6th Edition, April 2008

of the F/W SCSI bus without breaking the bus's termination. (Nodes attached to the
middle of a bus using a Y cable also can be detached from the bus without harm.) When
using in-line terminators and Y cables, ensure that all orange-socketed termination
packs are removed from the controller cards.
NOTE: You cannot use inline terminators with internal FW/SCSI buses on D and K
series systems, and you cannot use the inline terminator with single-ended SCSI buses.
You must not use an inline terminator to connect a node to a Y cable.
Figure 4-1 shows a three-node cluster with two F/W SCSI buses. The solid line and the
dotted line represent different buses, both of which have inline terminators attached
to nodes 1 and 3. Y cables are also shown attached to node 2.
Figure 4-1 F/W SCSI Buses with In-line Terminators
The use of in-line SCSI terminators allows you to do hardware maintenance on a given
node by temporarily moving its packages to another node and then halting the original
node while its hardware is serviced. Following the replacement, the packages can be
moved back to the original node.
Use the following procedure to disconnect a node that is attached to the bus with an
in-line SCSI terminator or with a Y cable:
162 Maintenance and Troubleshooting