[SunHELP] Keyboard wackiness?
sunhelp at sunhelp.org
Thu Aug 9 16:04:16 CDT 2001
Some PC's and Terminal Servers acting as consoles for Solaris systems send
a break signal when they power on or off. This causes the Solaris system to
drop down to the OK prompt unintentionally. Pulling out a keyboard from a
system and reconnecting it also causes the system to drop to the OK prompt.
How can we prevent this ?
This can be accomplished in many ways. Some of the recommended methods
are discussed below.
1.The file /etc/default/kbd can set a variable called KEYBOARD_ABORT.
Uncomment the line containing this variable in this file as shown below:
Then run the command "kbd -i" or simply reboot the system.The "kbd -i"
command will force the system to reread the /etc/default/kbd file.
This will permanently disable all the STOP+A and serial device break
signals on the system.
You can re-enable the break sequence by commenting out this line in the
/etc/default/kbd file and rebooting the system or running the "kbd -i"
2. You can enable/disable breaks with out changing any file entries
from the command line as well.
The " kbd -a enable" will enable the system to start accepting the
break signal and the "kbd -a disable" will disable the system from
accepting the break signal. These changes will be temporary and
be in effect only till the system reboots.
3. You can also reboot the system after setting the following variable
in /etc/system file as shown:
This will disable all break signals on the system.
Solaris 8 introduced a new feature which gives the system the
ability to force a hanging system to halt when required, without
allowing random or spurious Breaks to cause an unintentional stop. The
new sequence to stop the system is <RETURN> <TILDE> <CONTROL B>.There
must be an interval of more than 0.5 seconds between characters, and
the entire string must be entered in less than 5 seconds. This is true
only with serial devices acting as consoles and not for systems with
keyboards of their own.
This feature has been backported to Solaris 2.6 and Solaris 7 as well. The
patch 105924-10 for Solaris 2.6 and 107589-02 or higher for Solaris 7 is
required to enable this feature.
To enable the alternate boot sequence, just type "kbd -a alternate" or
if this change needs to be permanent, reboot the system after
uncommenting the following line in the /etc/default/kbd file :
Note: a) Do not uncomment the KEYBOARD_ABORT=disable line while doing this.
b) Do not set abort_enable=0 in /etc/system while doing this.
From: Ben Ricker [mailto:bricker at wellinx.com]
Sent: Thursday, August 09, 2001 1:40 PM
To: sunhelp at sunhelp.org
Subject: [SunHELP] Keyboard wackiness?
I had a weird problem. We house a Sun E250 at a CoLo site. I have a Sun
keyboard plugged into it. I mistook the Sun keyboard for another
keyboard (which I used for Linux machines) and unplugged it. I thought
nothing of it and plugged the Sun keyboard back in.
Came back to my desk and the Sun was dead; no pings, nothing. Went back
to CoLo and the terminal showed the 'Ok' prompt (single-user mode?).
What the heck happened there?
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