SYSCTL.CONF(5) File Formats Manual SYSCTL.CONF(5)

sysctl.confkernel state defaults

The /etc/sysctl.conf file is read in when the system goes into multi-user mode to set default settings for the kernel. The /etc/sysctl.conf is in the format of the sysctl(8) command, i.e.


Comments are denoted by a “#” at the beginning of a line.

Initial settings for sysctl(8).

To disable coredumps, you may use a configuration like:

# Disable coredumps.


The sysctl.conf file appeared in FreeBSD 4.0.

If loadable kernel modules are used to introduce additional kernel functionality and sysctls to manage that functionality, sysctl.conf may be processed too early in the boot process to set those sysctls.

August 3, 2007 macOS 14.1