Alternative to crashdump?
rwatson at FreeBSD.org
Thu Mar 26 14:11:09 PDT 2009
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
University of Cambridge
More information about the freebsd-current