IBM SG24-5131-00 manual Non TCP/IP Networks, Cabling Considerations

•Scan the /tmp/hacmp.out file to confirm that the /etc/rc.net script has run successfully. Look for a zero exit status.

•If IP address takeover is enabled, confirm that the /etc/rc.net script has run and that the service adapter is on its service address and not on its boot address.

•Use the lssrc -g tcpip command to make sure that the inetd daemon is running.

•Use the lssrc -g portmap command to make sure that the portmapper daemon is running.

•Use the arp command to make sure that the cluster nodes are not using the same IP or hardware address.

3.2.2Non TCP/IP Networks

Currently three types of non-TCP/IP networks are supported:

•Serial (RS232)

•Target-mode SCSI

•Target-mode SSA

While we use the word serial here to refer to RS232 only, in HACMP definitions, a “serial” network means a non-TCP/IP network of any kind. Therefore, when we are talking about HACMP network definitions, a serial network could also be a target-mode SCSI or target-mode SSA network.

The following describes some cabling issues on each type of non-TCP/IP network, how they are to be configured, and how you can test if they are operational.

3.2.2.1 Cabling Considerations

RS232 Cabling a serial connection requires a null-modem cable. As often cluster nodes are further apart than 60 m (181 ft.), sometimes modem eliminators or converters to fiber channel are used.

TMSCSI If your cluster uses SCSI disks as shared devices, you can use that line for TMSCSI as well. TMSCSI requires Differential SCSI adapters (see Chapter 2.3.2.3, “Supported SCSI Adapters” on page 26). Because the SCSI bus has to be terminated on both ends, and not anywhere else in between, resistors on the adapters should be removed, and cabling should be done as shown in Figure 11 on page 77, that is, with Y-cables that are terminated at one end connected to the adapters where the other end connects to the shared disk device.

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