Sysctl

Welcome to Sysctl.

Kernel Competence
Sysctl	Kldstat	Third-party Kernel Modules
Kernel Modules	FreeBSD Ports: Kld	Kenv
Compiling a new GhostBSD kernel
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Introduction

The sysctl utility retrieves kernel state and allows processes with appropriate privilege to set kernel state. The state to be retrieved or set is described using a “Management Information Base” (“MIB”) style name, described as a dotted set of components.

Usage

The information available from sysctl consists of integers, strings, and opaque types. The sysctl utility only knows about a couple of opaque types, and will resort to hexdumps for the rest. The opaque information is much more useful if retrieved by special purpose programs such as ps(1), systat(1), and netstat(1).

Some of the variables which cannot be modified during normal system operation can be initialized via loader(8) tunables. This can for example be done by setting them in loader.conf(5). Please refer to loader.conf(5) for more information on which tunables are available and how to set them.

Retrieve Kernel Information

Use sysctl plus the following NAME:

sysctl NAME

You will get the following examples:

NAME	Output on GhostBSD
kern.ostype	FreeBSD
kern.osrelease	12.1-STABLE
kern.osrevision	199506
kern.osreldate	1201512 You get the same result with the command: uname -U
kern.version	FreeBSD 12.1-STABLE GENERIC
kern.hostname	slughorn.ghostbsd-pc.home
kern.clockrate	{ hz = 1000, tick = 1000, profhz = 8128, stathz = 127
kern.boottime	Fri Feb 21 18:58:27 2020 (example)
kern.bootfile	/boot/kernel/kernel
kern.corefile	%N.core
kern.logsigexit	1
security.bsd.suser_enabled	1
security.bsd.see_other_uids	1
security.bsd.unprivileged_proc_debug	1
security.bsd.unprivileged_read_msgbuf	1
vm.loadavg	{ 0,59 0,52 0,54 }
hw.machine	amd64
hw.model	AMD Athlon(tm) 64 X2 Dual Core Processor 6000+
hw.ncpu	2
hw.byteorder	1234
hw.physmem	3972182016
hw.usermem	3445424128
hw.machine_arch	amd64
hw.realmem	4294967296
user.cs_path	/usr/bin:/bin:/usr/sbin:/sbin
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