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SYSCTL.CONF(5) FreeBSD File Formats Manual SYSCTL.CONF(5)
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.
For kernel modules loaded via rc.subr(8) system, additional module-
specific settings can be applied by adding a file in the same format
named /etc/sysctl.kld.d/<modulename>.conf.
FILES
/etc/rc.d/sysctl rc(8) script which processes sysctl.conf early
on in the process of transitioning to multi-
user mode.
/etc/rc.d/sysctl_lastload rc(8) script which processes sysctl.conf
shortly before the system reaches the multi-
user mode.
/etc/sysctl.conf Initial settings for sysctl(8).
/etc/sysctl.conf.local Machine-specific settings for sites with a
common /etc/sysctl.conf.
/etc/sysctl.kld.d Module specific settings for kernel modules
loaded via rc.subr(8).
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)
SEE ALSO
rc.conf(5), rc(8), sysctl(8)
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. Please
consult rcorder(8) to learn more about the ordering of rc(8) scripts.
FreeBSD 14.0-RELEASE-p11 June 30, 2022 FreeBSD 14.0-RELEASE-p11