OpenBSD operating system supports serial console. You can use the serial console for the following purpose:
- Remote server management.
- See console output.
- Debugging the server problem.
- Headless OpenBSD installation via network/PXE boot.
Configuration: Setup a serial console
To direct the boot process to use the serial port as a console, edit /etc/boot.conf, enter:
# vi /etc/boot.conf
Edit / append as follows:
set tty com0
The above will use first serial port as your console. You can also define baud rate (default baud rate is set to 9600bps). Append the following line to /etc/boot.conf (set baud rate to 115200):
stty com0 115200
Save and close the file. Reboot the server to test your configuration.
How do I connect to a serial console under Unix/OpenBSD/Linux?
You can also use client tool such as cu, scree, putty (Windows based), and putty for management purpose:
screen /dev/serialdevice 19200,cs8
cu -l /dev/serialdevice -s baud-rate-speed
You can also use minicom, ipmi or KVM over IP clients:
Sample session:
See also
- HowTo: Linux serial console
- HowTo: FreeBSD serial console
- OpenBSD man page ttys [openbsd.org] and boot.conf [openbsd.org]
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1 comment
This was second hit on my google search, so I thought I’d add a comment that might help someone else:
When connecting from an OpenBSD computer, the cu(1) command is available. It has always been part of the OpenBSD base install, and is often overlooked. A simple “cu -l /dev/cua00 -s 115200” will allow you to connect to the serial console. No need to add packages. Note: To leave cu you need to type “~.”, neither Esc nor Ctrl-C will work.