HP Serviceguard Extension for RAC (SGeRAC) manual W Scsi Buses with Inline Terminators

the bus without harm.) When using inline 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 19 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 19 F/W SCSI Buses with Inline Terminators

The use of inline 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 inline SCSI terminator or with a Y cable:

1.Move any packages on the node that requires maintenance to a different node.

2.Halt the node that requires maintenance. The cluster will reform, and activity will continue on other nodes. Packages on the halted node will switch to other available nodes if they are configured to switch.

3.Disconnect the power to the node.

4.Disconnect the node from the inline terminator cable or Y cable if necessary. The other nodes accessing the bus will encounter no problems as long as the inline terminator or Y cable remains connected to the bus.

5.Replace or upgrade hardware on the node, as needed.

6.Reconnect the node to the inline terminator cable or Y cable if necessary.

7.Reconnect power and reboot the node. If AUTOSTART_CMCLD is set to 1 in the /etc/ rc.config.d/cmcluster file, the node will rejoin the cluster.

8.If necessary, move packages back to the node from their alternate locations and restart them.

Replacing Disks 135