FreeBSD

FreeBSD is a Unix-like operating system descended from the Berkeley Software Distribution (BSD). Unlike Linux, the FreeBSD project maintains a complete operating system and is licensed under the more permissive BSD license.

Configuration

Most of the configuration for the operating system can be made by editing/etc/rc.conf.

Network

Similar to Linux, network adapters and their settings can be displayed using ifconfig.

The machine hostname can be set by defining the hostname value in /etc/rc.conf. Eg:

hostname="freebsd"

DHCP

To use DHCP, add the following lines to /etc/rc.conf:

ifconfig_bge0="DHCP"
ifconfig_bge0_ipv6="inet6 accept_rtadv"

Where bge0 is the interface name.

Static

For static IP assignment, edit /etc/rc.conf:

ifconfig_bge0="inet 10.0.0.3 netmask 255.255.255.0"
defaultrouter="10.0.0.1"

Applying Network Changes

Apply any network configuration changes by restarting these services:

# /etc/rc.d/netif restart
# /etc/rc.d/routing restart

Package Management

There are two ways to obtain software on your FreeBSD machine: Through precompiled packages, or using FreeBSD Ports. Both will be covered in the sections below.

Pkg Package Management

pkg is package management utility that downloads and installs packages from FreeBSD's pkg service at http://pkg.freebsd.org/ and is available on FreeBSD versions after 10.x.

Bootstrap the system by running /usr/sbin/pkg, or install it through ports under /usr/ports/ports-mgmt/pkg.

If you are familiar with yum or dnf, this table may help:

RedHat / Fedora	FreeBSD	Description
rpm -qa	pkg info [pkg name]	Returns a list of installed packages
yum install [package]	pkg install [package]	Installs a package with its dependencies
yum remove [package]	pkg delete [package]	Removes the package from the system
yum update	pkg upgrade	Updates installed packages
package-cleanup --leaves or dnf [list] autoremove	pkg autoremove	Removes leaf dependencies
yum clean [all]	pkg clean [-a]	Cleans package cache information

A neat feature for the security conscious is pkg audit -F which lists all known vulnerabilities for software that is installed on the system.

FreeBSD Ports

The port system automates building and installing packages on your system from source. Rather than trusting pre-compiled 3rd party packages, the ports system allows you to customize and compile a software package along with its dependencies.

To get started, updates the ports collection on your system:

## Download the ports collection to /var/db/portsnap
# portsnap fetch
## ... and extract it to /usr/ports
# portsnap extract

You may want to update the ports collection to get software updates periodically in the future. To do so, run:

# portsnap fetch update

To compile and install a port, go to the directory of the port to be installed and then run make install.

Most packages have configurations that can be customized. For larger packages with many dependencies, this may become unwieldy. There are two ways around this: One is to ask for all the customization options up front by running make config-recursive prior to make install; the other is to use the default options by setting the environment variable BATCH=yes.

After building a port, it is a good idea to clean the port's working directory to reduce wasted space by running make clean.

To remove an installed port, use either pkg delete or run make deinstall in the port's directory.

There are utilities that make using ports more convenient. portmaster works like a package manager by automating upgrades and installs on the system. Eg:

Command	Description
# portmaster -a	Automatically upgrade all outdated ports
# portmaster -af	Automatically upgrade and rebuild all ports
# portmaster shells/bash	Automatically builds and installs the port package

Checking for Updates

Regardless of which method you used to install packages, you can check for newer versions of packages or ports by updating ports or the package cache and then running:

# pkg version -1 "<"

System Update

Security updates can be applied to the FreeBSD system by using the freebsd-update utility . This utility can also be used to upgrade a system to a newer major or minor release.

Command	Description
$ freebsd-update fetch	Downloads outstanding patches. Files will be stored in /var/db/freebsd-update/
$ freebsd-update cron	Downloads outstanding patches (scheduled as a cronjob)
$ freebsd-update install	Installs any downloaded packages
$ freebsd-update rollback	Rolls back the last set of changes.
$ freebsd-update -r 10.1-RELEASE upgrade	Upgrades the system to the specified release

Depending on the type of updates performed, a restart may be necessary (ie. kernel and kernel modules).

When upgrading between minor releases, the ABI should remain the same and any installed applications should continue working. For upgrades between major releases, the ABI may change and any installed applications may break. To force an upgrade on all installed applications:

# pkg-static upgrade -f
## or ports (pass -G to use generic options)
# portmaster -af

After an upgrade, you may wish to reduce the amount of space used by deleting old update files. Do this only after you are sure you do not need to run freebsd-update rollback.

# find /var/db/freebsd-update/files/ -type f -exec rm -v '{}' +

Build a Custom Kernel

Checkout the kernel source to /usr/src via SVN:

# svn checkout https://svn.freebsd.org/base/stable/ /usr/src
 
# ARCH=$(uname -m)
# cd /usr/src/sys/$ARCH/conf/
# cp GENERIC MYCONF

Edit MYCONF if needed, and compile:

# cd /usr/src/
# make -j4  buildkernel   KERNCONF=''MYCONF''
# sudo make installkernel KERNCONF=''MYCONF''

The new kernel should now be installed and should run on the next rebot:

$ sysctl kern.conftxt

Note: compiling the kernel needs quite a bit of disk space. A FreeBSD-10.2 installation took over 2 GB:

1.1 GB  /usr/obj/usr/src/sys/MYCONF
 1.5 GB  /usr/src/

Configuration

Encrypted swap

• Hardening/FreeBSD

Linux compatibility

Mount linuxprocfs and install linux-f10-procps:

$ grep ^lin /etc/fstab 
linprocfs       /compat/linux/proc linprocfs rw 0       0
linsys          /compat/linux/sys  linsysfs  rw 0       0
 
$ sudo mkdir -p /compat/linux/{proc,sys}
$ sudo mount /compat/linux/proc && sudo mount /compat/linux/sys

$ sudo pkg install linux-f10-procps

Set linux_enable="YES" in /etc/rc.conf.

Screensaver

On this laptop I wanted to have the LCD shut off when the (text) console was idle

$ cat /etc/rc.conf
[...]
apm_enable="YES"
blanktime="60"
saver="blank"

Enable APM in device.hints

$ grep apm.0.disabled /boot/device.hints 
hint.apm.0.disabled="0"

SMART

To enable Template:WP, use smartmontools:

pkg install smartmontools
echo 'smartd_enable="YES"' >> /etc/rc.conf
cp -i /usr/local/etc/smartd.conf.sample /usr/local/etc/smartd.conf

Start smartd and

/usr/local/etc/rc.d/smartd start

The installation package should have created /usr/local/etc/periodic/daily/smart to check on monitored devices periodically.

Memory

FreeBSD memory notation is quite different, let's explain it in short:

$ top -b -d 1 | grep -A1 ^Mem
Mem: 112M Active, 687M Inact, 158M Wired, 8268K Cache, 87M Buf, 12M Free
Swap: 1024M Total, 41M Used, 983M Free, 3% Inuse

• Active: Memory currently being used by a process
• Inactive: Memory that has been freed but is still cached since it may be used again.
• Wired: Memory in use by the Kernel. This memory cannot be swapped out
• Cache: Memory being used to cache data, can be freed immediately if required
• Buffers: Disk cache
• Free: Memory that is completely free and ready to use.

Links

• FreeBSDwiki