IBM SG24-5131-00 manual Configuring Target Mode SSA, Testing RS232 and Target Mode Networks

3.2.2.4 Configuring Target Mode SSA

The node number on each system needs to be changed from the default of zero to a number. All systems on the SSA loop must have a unique node number.

To change the node number use the following command:

chdev -l ssar -a node_number=#

To show the system’s node number use the following command:

lsattr -El ssar

Having the node numbers set to non-zero values enables the target mode devices to be configured. Run the cfgmgr command to configure the tmssa# devices on each system. Check that the tmssa devices are available on each system using the following command:

lsdev -C grep tmssa

The Target Mode SCSI or SSA serial network can now be configured into an HACMP cluster.

3.2.2.5 Testing RS232 and Target Mode Networks

Testing of the serial networks functionality is similar. Basically you just write to one side’s device and read from the other.

Serial (RS323): After configuring the serial adapter and cabling it correctly, you can check the functionality of the connection by entering the command

cat < /dev/ttyx

on one node for reading from that device and

cat /etc/environment > /dev/ttyy

on the corresponding node for writing. You should see the first command hanging until the second command is issued, and then showing the output of it.

Target Mode SSA: After configuration of Target Mode SSA, you can check the functionality of the connection by entering the command:

cat < /dev/tmssax.tm

on one node for reading from that device and:

Cluster Hardware and Software Preparation 65