How do I reload sysctl from sysctl.d directory?
As documented, for recent util-linux versions:
# Load settings from all system configuration files sysctl --system
For older versions (that is, if --system does not work):
# Load settings from /etc/sysctl.conf sysctl -p
# Load settings from the specified file sysctl -p /etc/sysctl.d/<whatever>.conf
The README file in /etc/sysctl.d/ on an Ubuntu 12.04 system with procps 1:3.2.8-11ubuntu6.3 says to run:
service procps start
Which ends up running (via /etc/init/procps.conf) this:
cat /etc/sysctl.d/*.conf /etc/sysctl.conf | sysctl -e -p -