Subject: Re: "core-less" kernel crashes
To: Laine Stump <>
From: John Hawkinson <jhawk@MIT.EDU>
List: current-users
Date: 01/21/2001 14:51:21
In message <>, Laine Stump writes:
>John Hawkinson <jhawk@MIT.EDU> writes:
>> That's not good. Do you have a persistent message buffer across
>> reboots?
>I don't think that's possible on a PC - the BIOS clears all of memory
>during the POST memory test (at least it used to 10 years ago, and I
>assume they haven't changed the behavior since then...)

Is that a "No" or an "I don't know?". My VAIO preserves the message
buffer across reboots.

>> If you have DDB compiled in, the system will print a stack
>> trace to the console if entry to ddb is not enabled, before rebooting.
>Hmm, I didn't know it was posible to have DDB enable without enabling
>"entry to ddb". What should my options be for that?

options DDB controls whether it is compiled in. The sysctl
ddb.onpanic controls whether a panic takes you into ddb.

>> If you have a persistent message buffer, you can find this with dmesg.
>> If not, you could hook up a serial console and and log the output.
>That sounds like a good idea - I'll hook something up and hope that
>it crashes again.