Alternative to crashdump?

[Robert Watson]

On Thu, 26 Mar 2009, Barney Cordoba wrote:

> I have a 7.0 server which crashes every now and then and it always seems to 
> happen when its unattended. Also, crashdump doesn't work reliably on the MB, 
> so thats not an option either without a lot of work I don't have time for.
>
> Is there a way to get ddb to save the crash trace and then reboot? I just 
> really need to crashpoint and get the trace. Even just the crash point would 
> be very useful. I can't have it drop into the keyboard for half the night, 
> or to reboot and lose the info.

DDB does support dumping only DDB output to disk, which might be more reliable 
a that writes less data, but I believe that was introduced in 7.1 
(textudmp(4)).  However, if it's simply a case of the disk controller not 
working in your crash environment, perhaps because it's involved in the crash, 
then the usual solution is to attach a serial console via another box and log 
output.  You can use either KDB_UNATTENDED with KDB_TRACE to generate a trace 
automatically on panic and reboot , or you can use the ddb script environment 
(also 7.1, I think?) to run sets of DDB commands and automatically reboot.

Robert N M Watson
Computer Laboratory
University of Cambridge