FreeBSD securelevel
Securelevel is a security mechanism implemented in the kernel.
To check current ‘secure level’:
$ sysctl kern.securelevel
kern.securelevel: 2
To change / raise ‘secure level’:
$ sysctl kern.securelevel=2
To enable ‘secure level’ on boot:
$ sysrc kern_securelevel_enable="YES"
kern_securelevel_enable: -> YES
$ sysrc kern_securelevel="2"
kern_securelevel: -> 2