NAME

sysctl.conf —

kernel state defaults

DESCRIPTION

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 file is in the format of the sysctl(8) command, i.e.,

sysctl_mib=value

Comments are denoted by a “#” at the beginning of a line. Comments can also exist at the end of a line, as seen in the EXAMPLES section, below.

FILES

/etc/sysctl.conf: Initial settings for sysctl(8).
/etc/sysctl.conf.local: Machine-specific settings for sites with a common /etc/sysctl.conf.

EXAMPLES

To turn off logging of programs that exit due to fatal signals you may use a configuration like

# Configure logging.
kern.logsigexit=0	# Do not log fatal signal exits (e.g., sig 11)

HISTORY

The sysctl.conf file appeared in FreeBSD 4.0.

BUGS

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. For example, sysctls to manage the Linux compatibility layer (linux(4)) cannot be set in sysctl.conf if the Linux compatibility layer is loaded as a module rather than compiled into the kernel.