Subject: Re: SysV IPC works... but how to I get a crash dump?
To: None <>
From: Szabolcs Szigeti (PinkPanther) <>
List: current-users
Date: 12/01/1993 15:33:22
Hi, (Simon J. Gerraty) writes:

  [ stuff deleted ]
> gets some sort of trap - sorry the system resets itself much too
> quickly, so all I can spot is "trap".  Savecore (I created /var/crash)
> seems to find nothing so I have no other evidence.
   [ more stuff deleted ]
> As for save core, I have 16Mb RAM and two 16Mb swap partitions, I
> suspect I need to force crash dumps into the 2nd partion so that they
> are still intact by the time savecore runs (yes it does run) since it
> finds nothing.  I'm assuming a panic or reset of this nature would
> have left a dump?  If not how can I force this to be done.

I have experienced the same things, not just with shared mem, but any other
panic: the system in fact can not create a vmcore, it gets a trap while
trying to dump, then reboots. Using DDB I can see the trap, it is some 
vm_fault. It can even be triggered by calling panic or diediedie from
DDB.(I didn't have a real panic for months :-)) I suppose something in the
dump routine has to be wrong. 
I have an IDE drive, and don't know if other dump devices show the same
behaviour. Stangely enough the old 386bsd-0.1 was able to dump anytime it

> Any help appreciated, and if anyone can help me get a working kernel
> with DDB in it that would be great too.

Are you sure you have the kernel fully recompiled? -DDDB isn't visible
in the dependencies. 

> Thanks!
> --sjg