Using Netconsole

Some of our EVMs do not have a serial console. As a result of which we will be unable to see the kernel boot up log on a serial console. Netconsole proves to be useful in this case.

The netconsole documentation that comes with a linux kernel can be found here

And example command line would have the following to enable netconsole

console=netcon0 netconsole=4444@10.218.100.27/eth0,5555@10.218.100.247/00:39:f1:0b:73:25 ip=10.218.100.27

What does the above mean

- first we are using netcon0 as the console

- Netconsole needs a static IP address so ip=10.218.100.27 means that the EVM will boot up with an IP address 10.218.100.27

- Also netconsole is configured to use port 4444@ to send console messages to port 5555@/

To listen for console messages on the host that is to receive netconsole commands issue the following command:

% nc -l -u -p 5555

You should be able to see the kernel boot up log on the linux host machine



The screen shot below clearly shows how the various parameters passed to the kernel command line are getting used