Sascha Wildner described in a post to dragonfly.bugs,
dumpdev="/dev/ad0s1b"
placed in /etc/rc.conf will enable your system to save crash dumps in /var/crash, saving the effort of retyping them in a post. (“makeoptions DEBUG=-g” in your kernel config is also needed.)
I’ve always wondered why these settings were not default in development versions of OSs like DragonFly.
Sure knowledgable users know how to do this, but if all you needed to do was ask a new user to send a copy of a crash dump file that was automatically generated and saved, it might save the developers some headaches while trying to track down issues discovered by less technical folks.
well, vmcore files tend to eat up a lot of space. If you have e.g. 512 MB of mem, your vmcore will be 512 MB big. Also, not everyone has dfbsd installed on ad0s1 (like me). It makes more sense to enable the var in rc.conf by hand than to enable it as a default.
You are right that there could be a little blurb about it in the installation README.
Fair enough.
Just curious, but couldn’t there be a default option for a kernel only crash dump, like in Windows XP, and an optional full memory crash dump?
Seems like a reasonable compromise from my POV…