[Xen-users] Unable to connect to console via terminal console server (CentOS Xen kernel)

["vincenzo romero" <new2xen@xxxxxxxxx>]

Hello all,

Excuse in advanced if my problem has been documented in the past (I have not found specific issue upon searching).

Configuration of my CentOS was based upon a Help doc: http://www.cyberciti.biz/faq/linux-serial-console-howto/
Changes therefore were made to:
- HW bios to accept remote access on Baud speed 57600
- changes to /boot/grub/grub.conf and /etc/inittab per the above tech doc.

Problem Summary:  
---------------------------
Unable to connect to a CentOS server remotely via a Terminal Server connection.  For example:
[my.workstation] --------via.IP.telnet.to.terminal.server+portnumber-----------[CentOS Server running xen kernel]
telnet terminal_server_host 10010  (hostname_of_Terminal_SerialConsole_Server) [port number]

outcome:  
[root@myhost]# telnet ts1-rack-1 10010
Trying 192.10.2.50...
Connected to ts1-rack-1 (192.10.2.50).

Escape character is '^]'.

Troubleshooting:
-----------------------
1.  Tried to check if port connectivity at least exists;  typed following from the CentOS host:
cat /etc/inittab >/dev/ttyS0
result:  still nothing.

2.  Accessing a similar server via terminal server's remote console proved to be successful.  The grub.conf and inttab are the same; except for the kernel flavor (XEN):

a.  Problem machine's kernel: Linux badhost-centos 2.6.18-53.1.6.el5xen
b.  Good machine's kernel: Linux goodhost-centos 2.6.18-53.1.6.el5
(where the attempt to login to console via terminal server is successful):
  *  performed this in the goodhost-centos:  cat /etc/inittab >/dev/ttyS0
  *  /etc/inittab contents appear, as it should work

[root@atanato grub]# telnet ts1-rack-1 10001
Trying 10.100.2.50...
Connected to ts1-rack-1 (192.10.2.50).
Escape character is '^]'.
#
# inittab       This file describes how the INIT process should set up
#               the system in a certain run-level.
|
|
|
=============

FYI ... on both good and bad machines the following changes were made in:

1.  /boot/grub/grub.conf

added the lines:
serial --unit=1 --speed=57600
terminal --timeout=8 console serial

appended after each kernel line:
console=tty1 console=ttyS0,57600n8

# Run gettys in standard runlevels
co:2345:respawn:/sbin/agetty -h -L ttyS0 57600 vt100
c1:2345:respawn:/sbin/agetty -h -L ttyS1 57600 vt100
1:2345:respawn:/sbin/mingetty tty1
2:2345:respawn:/sbin/mingetty tty2
3:2345:respawn:/sbin/mingetty tty3
4:2345:respawn:/sbin/mingetty tty4
5:2345:respawn:/sbin/mingetty tty5
6:2345:respawn:/sbin/mingetty tty6

Question:
-------------
- is this a known issue?  if so, what is the workaround?
- any suggestions would be greatly appreciated.

-- 
best,

Vince
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