Managing Serviceguard 12th Edition, March 2006

Planning and Documenting an HA Cluster
Hardware Planning
Chapter 4 139
RS232 Information
If you plan to configure a serial line (RS232), you need to determine the
serial device file that corresponds with the serial port on each node.
1. If you are using a MUX panel, make a note of the system slot number
that corresponds to the MUX and also note the port number that
appears next to the selected port on the panel.
2. On each node, use ioscan -fnC tty to display hardware addresses
and device file names. For example:
# ioscan -fnC tty
This lists all the device files associated with each RS232 device on a
specific node.
3. Connect the appropriate RS-232 cable between the desired ports on
the two nodes.
4. Once you have identified the device files, verify your connection as
follows. Assume that node 1 uses /dev/tty0p0, and node 2 uses
/dev/tty0p6.
• From a terminal on node 1, issue the following command:
# cat < /dev/tty0p0
• From a terminal on node 2, issue the following command:
# cat /etc/passwd > /dev/tty0p6
The contents of the password file should be displayed on the
terminal on node 1.
5. On the worksheet, enter the following:
RS232 Device File
Enter the device file name corresponding to the serial
interface to be used on this node. This parameter is
known as SERIAL_DEVICE_FILE in the ASCII
configuration file.
Second Node Name
Enter the name of the node that will be connected to
this node via RS232. a node name can be 31 bytes or
less.