The Lconsole utility provides a serial port console that lets you do the following:
Use serial lines to get the boot prompt in case of a network failure.
Perform a remote reset in case of hardware failure. console can only power cycle a single node at once.
 | Note: Lconsole requires that you use a serial multiplexer.
Do not attempt to use Lconsole and the Hoover cluster manager together. |
Lconsole consists of the following commands, which are installed on the remote administration node (that is, the node to which the serial multiplexer is connected, which may or may not be the head node):
The /var/Lconsole/logs directory contains Lconsole logs.
This chapter tells you how to do the following:
You can configure the cluster to do the following:
Send boot messages to the remote administration node
Note: Boot messages can go to either the monitor (the default) or the serial console; however, they cannot be seen in both places. Permit login to the other nodes on their serial ports
By default, boot messages are sent to the monitor. To send them to the remote administration node instead, do the following on each nonadministration node:
Edit the /etc/lilo.conf file so that it redirects all boot messages to the serial console:
serial=tty#,baudrate_parity(n|e|o)_bits(7|8)
The variables are as follows:
tty# is the number of the serial port; 0 corresponds to COM1 alias /dev/ttyS0.
baudrate is the baud rate of the serial port in bits per second (b/s).
parity(n|e|o) is the parity used on the serial line: n for no parity, e for even parity, o for odd parity.
bits(7|8) is the number of bits in a character. If the parity value is n, the default is 8; if the parity value is e or o, the default is 7.
For example, to use port /dev/ttyS0 with a baud rate of 9600 b/s, no parity, and 8 bits per character, enter the following:
serial=0,9600n8
Under each image area in the /etc/lilo.conf file, add the following:
append="console=serial_device_in_/dev"
For example:
append="console=ttyS0"
The following example shows an entire /etc/lilo.conf file, with added portions highlighted:
boot=/dev/hda map=/boot/map install=/boot/boot.b prompt timeout=50 serial=0,9600n8 image=/boot/vmlinuz-2.2.5-15 label=linux root=/dev/hda1 initrd=/boot/initrd-2.2.5-15.img read-only append="console=ttyS0" image=/boot/bzImage label=new root=/dev/hda1 initrd=/boot/initrd-2.2.5-15.img read-only append="console=ttyS0"
For more information, see the lilo.conf(5) man page.
To permit login on the serial port of a nonadministration node, add the following to the /etc/inittab file on that node:
device#:run_levels:action:getty_program device speed |
These items must match what is in the /etc/lilo.conf file.
For example, for the Red Hat base OS:
S0:2345:respawn:/sbin/uugetty ttyS0 DT9600 |
This means:
The device is /dev/ttyS0
It can run in levels 2, 3, 4, and 5
The uugetty program will be executed, and if it dies it will be restarted (respawn)
The device speed is DT9600
For more information, see the inittab(5) and getty(8) man pages.
On the remote administration node, do the following:
Edit the /etc/services file so that it contains the port number to be used for Lconsole. The recommended port is 5000, but you can choose another free port if you want. For example:
# Lconsole lctelnet 5000/tcp
Edit the /etc/inetd.conf file (which describes the services that will be available through the INETD TCP/IP super server) to add the following line:
# Lconsole # lctelnet stream tcp nowait root /usr/Lconsole/bin/lctelnetd lctelnetd
The fields are as follows:
Service name: lctelnet
Socket type: stream
Protocol: tcp
Wait status: nowait
User: root
Server program: /usr/Lconsole/bin/lctelnetd
Server program arguments: lctelnetd
Create a file named /var/Lconsole/.LC/clustername/nodename for each nonadministration node. In the file, add the following:
Console port
Reset port
Logging options
For example, the file /var/Lconsole/.LC/acmecluster/node04 could contain the following:
#CONSOLE EMP USER BAUD LOG DFLTPW /dev/ttyR0 /dev/ttyR9 root 9600 yes yes
This means:
The console port is /dev/ttyR0
The emergency management port (EMP) is /dev/ttyR9
The user who can perform a reset is root
The baud rate is 9600
Logging to a file is turned on
The use of a default password (none) is turned on (if this field is no, then the user must supply a password)
| Note: The /dev/tty values above are device dependent and may change on site. |
To connect to the Linux console on the remote administration node, enter the following from any workstation on your network:
$ telnet hostname port |
For example, to log into a remote administration node named node04, enter the following:
$ telnet node04.acme.com 5000 Trying 192.168.0.4... Connected to node04.sgi.com. Escape character is '^]'. Red Hat Linux release 6.0 (Hedwig) Kernel 2.2.5-15 on an i686 LConsole Login: root Password: def... Lconsole Release 1.1 Copyright 1995-1998 Silicon Graphics, Inc.All Rights Reserved. Main Menu: Clusters ----------- 1. acmecluster |
You must then specify your Lconsole user name and password.
This section tells you how to use and exit from Lconsole.
The Lconsole utility allows you to perform the following functions on any node in the cluster:
For example, to connect to the console for node04, enter the following:
System 'node04':
Available Operations
--------------------
1. Connect to Serial Console
2. Hardware Reset
3. Power Up
4. Power Down
5. Steal Occupied Console Line
Enter choice (1 - 5) or '..' for Systems Menu: 1
----------- Connected port=/dev/ttyR1 -----------
9600 BAUD 8 NONE 1 SWFC=ON HWFC=OFF
CAR=OFF DTR=ON RTS=ON CTS=OFF DSR=OFF
Type ~X to Exit.
Connection Ready.
|
To exit from Lconsole, you must be at the main menu:
To leave the node console and return to the Available Operations menu, press ~X
To leave the Available Operations menu and return to the Available Systems menu, enter .. (dot dot)
To leave the Available Systems menu and return to the Main Menu, enter..(dotdot)
To exit from Lconsole from the Main Menu, enter q.
For example:
System 'node02':
Available Operations
--------------------
1. Connect to Serial Console
2. Hardware Reset
3. Power Up
4. Power Down
5. Steal Occupied Console Line
Enter choice (1 - 5) or '..' for Systems Menu: 1
----------- Connected port=/dev/ttyR3 -----------
9600 BAUD 8 NONE 1 SWFC=ON HWFC=OFF
CAR=OFF DTR=ON RTS=ON CTS=OFF DSR=ON
Type ~X to Exit.
Connection Ready.
Lconsole DINC closing...
~X
------------
Connect to Console done.
System 'node02':
Available Operations
--------------------
1. Connect to Serial Console
2. Hardware Reset
3. Power Up
4. Power Down
5. Steal Occupied Console Line
Enter choice (1 - 5) or '..' for Systems Menu: ..
Cluster 'acmecluster':
Available Systems
-----------------
1. node01
2. node02
3. node03
4. node04
Enter choice (1 - 4) or '..' for Main Menu: ..
Main Menu:
Clusters
---------------
1. acmecluster
Enter choice 1 or 'q' to Quit: q
Connection closed by foreign host. |
To add an Lconsole user, enter the following as root:
# /usr/Lconsole/bin/lcpasswd [username] password Re-enter password: password |
For example:
# /usr/Lconsole/bin/lcpasswd lhj Creating console User password for user lhj New console password: (password_not_shown) Retype new console password: (password_not_shown) lcpasswd: Success |
If you do not supply a username, the current login is the default. Passwords are stored in /usr/Lconsole/adm.
The same process is used to change the password for an existing user.