FreeBSD jails

Jails are a hardened version of chroots. They allow multiple separate FreeBSD installations to run on one machine, while sharing a kernel, ram, resources.

Documentation

man jail	https://www.freebsd.org/cgi/man.cgi?query=jail&apropos=0&sektion=0&manpath=FreeBSD+12.1-RELEASE+and+Ports&arch=default&format=html
man jail.conf	https://www.freebsd.org/cgi/man.cgi?query=jail.conf&apropos=0&sektion=0&manpath=FreeBSD+12.1-RELEASE+and+Ports&arch=default&format=html

Tutorials

excellent/comprehensive tutorial	http://clinta.github.io/freebsd-jails-the-hard-way/
FreeBSD Manual	https://www.freebsd.org/doc/handbook/jails.html

Locations

/etc/rc.conf	enable jails, global jail configuration
/etc/jail.conf	configure individual jails
/etc/jails/*.fstab	individual jail fstabs

Notes

jail usage

jail setup

jail maintenance

jail troubleshooting

Jail Management Tools

rctl	set jail resource restrictions
cbsd	abstraction layer over jails/bhyve/xen
iocage	more powerful tool to facilitate managing jails
ezjail	shellscript to facilitate managing jails