.\" Copyright (c) 1999 Chris Costello <chris@FreeBSD.org>
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.Dd July 21, 2018
.Dt SYSCTL.CONF 5
.Os
.Sh NAME
.Nm sysctl.conf
.Nd kernel state defaults
.Sh DESCRIPTION
The
.Pa /etc/sysctl.conf
file is read in when the system goes into multi-user mode to set default
settings for the kernel.
The
.Pa /etc/sysctl.conf
file is in the format of the
.Xr sysctl 8
command, i.e.,
.Bd -literal -offset indent
sysctl_mib=value
.Ed
.Pp
Comments are denoted by a
.Dq #
at the beginning of a line.
Comments can also exist at the end of a line,
as seen in the
.Sx EXAMPLES
section, below.
.Sh FILES
.Bl -tag -width /etc/sysctl.conf -compact
.It Pa /etc/sysctl.conf
Initial settings for
.Xr sysctl 8 .
.El
.Sh EXAMPLES
To turn off logging of programs that exit due to fatal signals you may use
a configuration like
.Bd -literal -offset indent
# Configure logging.
kern.logsigexit=0	# Do not log fatal signal exits (e.g., sig 11)
.Ed
.Sh SEE ALSO
.Xr rc.conf 5 ,
.Xr rc 8 ,
.Xr sysctl 8
.Sh HISTORY
The
.Nm
file appeared in
.Fx 4.0 .
.Sh BUGS
If loadable kernel modules are used to introduce additional kernel
functionality and sysctls to manage that functionality,
.Nm
may be processed too early in the boot process to set those sysctls.
For example, sysctls to manage the Linux compatibility layer
.Po
.Xr linux 4
.Pc
cannot be set in
.Nm
if the Linux compatibility layer is loaded as a module rather than
compiled into the kernel.