I have seen several questions regarding this, and must have tried nearly everything, but still, Apache won't create a core dump on the production server.
This is the setup that actually works on my VM:
apt-get install gdb apache2-dbg php5-dbg libapr1-dbg libaprutil1-dbg
mkdir /tmp/apache-coredumps
chmod g+w,o+w /tmp/apache-coredumps/
cat <<EOF > /etc/apache2/conf.d/debugging
CoreDumpDirectory /tmp/apache-coredumps
EOF
ulimit -c unlimited
apache2ctl -t && service apache2 restart
On the VM, with "kill -11 " I can see "possible coredump in /tmp/apache-coredumps" in the logfile, but this part is missing on the production server.
This is what I also tried:
- sysctl fs.suid_dumpable=2
- sysctl kernel.core_pattern=/tmp
- Set ulimit in Apache's init script as stated in https://passwd.org/2012/03/apache-httpd-core-dump-instructions
- Used "CoreDumpDirectory /var/cache/apache2"
Server and VM both are Debian Wheezy running Apache 2.2.22 (mpm-prefork), PHP 5.4.45.
What else might be blocking the creation of a core dump?
Best Answer
Hope this helps someone.
Note that if you have
PrivateTmp=trueset in your/usr/lib/systemd/system/apache2.service(or whatever it's called on your system), meaning Apache actually looks for/tmpinside something like/tmp/systemd-private-c27fc5b152d546159d675e170641529b-apache2.service-IcEt0m/, Apache won't be able to write to that dir and you won't get cores dumped at all (due to thesystemdtmp directory having 700 root-only perms).The solution is to either set
PrivateTmp=falseor modify the permission of the systemd tmp directory after the server starts.I wasted hours on this to only just now finally realize what the problem was.