Tue Nov 1 14:55:36 EET 2011

List and get rid of obsolete program core dump files and completely disable core files on FreeBSD

My FreeBSD router has started running out of space, I looked for ways to clean up some space. So I remembered some programs are generating core files while they crash. Some of these files are really huge and ban be from 1Mb to > 1G.


I used find to first list all my produced core files starting from root directory (/) , like so:

find / -name core -exec du -hsc {} \;
....


Having a list of my core files with the respective core file size and after reviewing, I deleted one by one the cores which were there just taking up space.
It's a wise idea that core dumps file generation on program crash is completely disabled, however I forgot to disable cores, so I had plenty of the cores - (crash files which are handy for debug purposes and fixing the bug that caused the crash).

Further on I used an /etc/rc.conf - dumpdev=NO , variable which instructs the kernel to not generate core files on program crash:

freebsd# echo 'dumpdev=NO' >> /etc/rc.conf


Next, to make dumpdev=NO , take affect I rebooted the server:

freebsd# shutdown -r now
...


There is a way to instruct every server running daemon to know about the newly set <> dumpdev=NO by restarting each of the services with their init scripts individually, but I was too lazy to do that.