Configuring Text Console For SSH Connectivity

 

This process involves modifying:

BIOS Settings

DRAC Settings

/boot/grub/grub.conf

/etc/securetty

/etc/inittab (for RHEL5), or /etc/init/ttyS1.conf (for RHEL6)

We use mcctest (RHEL5) and mcctest1 (RHEL6) for examples.  On Linux, the serial ports COM1, CO M2, are named as ttyS0, ttyS1. We use the second serial port ttyS1 for console redirection.

1) Change respective BIOS settings

Bios settings for "Serial Communication"

Serial Communication - On with Console Redirection via COM2

Serial Port Address - Serial Device1=COM1, Serial Device2=COM2

External Serial Connector - SerialDevice1

Failsafe Baud Rate -  57600

Remote Terminal Type - ANSI

Redirection After Boot – Enabled

This is to redirect console via COM2.

2) Change respective rackadm settings

Use  /opt/dell/srvadmin/sbin/racadm. This should be already set properly by default. First check the configuration, and make sure

[root@mcctest ~]# racadm getconfig -g cfgSerial

cfgSerialBaudRate=57600

cfgSerialConsoleIdleTimeout=600

cfgSerialSshEnable=1

...

Make changes if necessary via

[root@mcctest ~]# racadm config -g cfgSerial -o cfgSerialConsoleIdleTimeout 600

[root@mcctest ~]# racadm config -g cfgSerial -o cfgSerialSshEnable 1

[root@mcctest ~]# racadm config -g cfgSerial -o cfgSerialBaudRate 57600

This is to enable SSH to access DRAC.

3) Enable agetty for ttyS1

This is required to start agetty for ttyS1 at booting time.

Add following entry in /etc/inittab

co:2345:respawn:/sbin/agetty -h -L 57600 ttyS1 ansi

           Add/Edit appropriate entries in  /etc/init/ttyS1.conf

mcctest1 $ cat  /etc/init/ttyS1.conf

# # ttyS0 - agetty

# #

# # This service maintains a agetty on ttyS0.

#

# stop on runlevel [S016]

# start on runlevel [23]

#

# respawn

# exec agetty -h -L -w /dev/ttyS0 115200 vt102

start on stopped rc RUNLEVEL=[2345]

stop on starting runlevel [016]

respawn

exec /sbin/agetty /dev/ttyS1 57600 ansi

4) Add/Edit appropriate entried in  /boot/grub/grub.conf

This is needed in order to redirect OS loading to console as well via ttyS1 (or COM2).

These two entries need to be added into grub.conf
serial –unit=1 –speed=57600
terminal –timeout console serial

And append "console=ttyS1,57600" to your kernel entry.

Note – in grub.conf file you need to comment out couple of entries and add/edit some entries.

Entries in grub.conf –

#splashimage=(hd0,0)/boot/grub/splash.xpm.gz

#hiddenmenu

serial --unit=1 --speed=57600

terminal --timeout console serial

.....

........

title Red Hat Enterprise Linux Client (2.6.18-274.7.1.el5PAE)

        root (hd0,0)

        kernel /boot/vmlinuz-2.6.18-274.7.1.el5PAE ro root=/dev/sda1 console=ttyS1,57600 console=tty0

        initrd /boot/initrd-2.6.18-274.7.1.el5PAE.img

5) Add appropriate entry in /etc/securetty

Add following entry in /etc/securetty –

ttyS1

This is needed for root access to the console.

6) Connect to console using ssh

divekar@mcclogin $ ssh mcctest-mgt -l root

root@mcctest-mgt's password:

Depending on the version of DRAC, you may connect to the console via

console com2

or

connect com2

7) Disconnect

To disconnect from ssh connection to console , enter   “Control-\” (i.e. ^\).

Issue and solution:

1) Problem - logged on to mcctest1-mgt using ssh. After that cannot connect to console.

$ connect com2

connect: com2 port is currently in use

Solution -

$  racadm  racreset

2) issue

Note – If you are using console from web server and you move your pointer out of that window, then when you again go to console window,  click on “View -> Refresh”. By this way you will regain control on the console window and can issue commands from console.

REF:

http://support.dell.com/support/edocs/software/smdrac3/idrac/idrac10mono/en/ug/html/racugc5.htm

Created by: Shashi Diverkar, 14-Jan-2013

Modified: 15-Jan-2013 (Jingchen Zhou)