System freeze on 6.1/2 when running makeworld and dump

[Adrian Wontroba]

On Sat, Jan 06, 2007 at 07:14:41PM +1100, Geoff Roberts wrote:
> I can consistantly make my system freeze when building makeworld and 
> running dump at the same time. The system actually locks - I have to 
> hit the reset switch to bring the system back to life.

I have an old SMP machine at work which sometimes does something similar
during its daily housekeeping, where Apache and Nagios are bounced and a
small MySQL database dumped. It sometimes appears to hang during the
database dump. The debugger shows many processes waiting for UFS. I
suspect that the problem starts several minutes earlier.

All of the following help to keep the problem away:
Upgrading from a several months old 5-STABLE to 6-STABLE.
Inserting 60 second delays at various points.
Disabling SMP.

No core dump available (Mylex disk controller).

My next diagnostic step will be a serial console.

-- 
Adrian Wontroba
The biggest mistake you can make is to believe that you are
working for someone else.