Getting a kerneldump. [Was: Re: panic: sorele ]

[Willem Jan Withagen]

> The thing is that I am not able to get a kernel dump.
> Although I have set the
> dumpdev="/dev/ad0s1b"
> dumpdir="/usr/crash"
> in /etc/rc.conf
> What I get is:
> Sep 27 18:06:59 proxy savecore: no dumps found
>
> Do I have to compile in something into the kernel so that it will be 
> able to make a dump or?
>
> Do I have to set something else to be able to get a kernel dump? Can 
> you please help me out here? I have created the /usr/crash directory 
> and there is lots of space in /usr partition(50gbyte) and the swap 
> device is /dev/ad0s1b and it is 16gbytes and 3gbytes physical RAM is 
> installed in the machine, so everything should be ok.
>
> Yet I am not able to get any crash dumps in /usr/crash directory. So 
> what am I missing?

One way to test this is, if you have the KDB debugger compiled in:

- break into the debugger; CTRL-ESC on you keyboard.
- at the prompt: call doadump
Ans see that 3Gb is written to disk.

Then reboot, and see savecore write the dump to disk.
Look at the flags of the manualpage to see if you can get more into out 
of savecore.

And you can also set flags in /etc/rc.conf.
savecore_flags="-v"

If this works, than all preconditions of getting a dump are met and you 
have to look elsewhere for trobule
If not, then this obviously needs to be fixed.

--WjW