Howto debug Kernel problems ? (jail -r -> freeze)

[Michiel Boland]

On 01/25/2012 16:09, Denny Schierz wrote:
>
> Am 25.01.2012 um 16:00 schrieb Marius Strobl:
>>
>> Not that I'm aware of. Do you have a kernel built with options
>> BREAK_TO_DEBUGGER? Does it work when the machine doesn't hang
>
> jupp, I have
>
>> (you can resume via the "continue" command in the kernel
>
> works too
>
>> debugger)? Do you send the break via the "break" command of the
>> ALOM or by sending a break via a terminal attached to the ALOM
>> console?
>
>
> ssh alom ->  login ->  type break ->  type console -f ->  normal freebsd console
>
> but, It happens nothing. I expected to get into the kdb.
>
> cu denny

What happens if you do

# sysctl debug.kdb.alt_break_to_debugger=1

then type the alternate break sequence (Enter ~ ^B) on the console?