DragonflyBSD

Fred, Mascot of DragonflyBSD

DragonflyBSD is a free, UNIX-like operating system based on FreeBSD, that is part of the BSD family focused on performance and optimization. It is based on the same UNIX ideals and APIs and shares ancestor code with other BSD operating systems.

It contains a bunch of useful features which sets it apart from other BSD/Linux-based operating systems, one being HAMMER - it's own high-performance filesystem with built-in mirroring and historic access functionality.

Other features include:

• Virtual kernels providing the ability to run a full-blown kernel as a user process for the purpose of managing resources or for accelerated kernel development and debugging
• Token-based synchronisation mechanism for it's kernel, in turn allowing for DragonflyBSD to parallelize the system with less effort compared to other kernels, which primarily use hard mutex locks.
• Optimised for SSD usage by utilising a swapcache.
• Instant readable/writeable snapshots

Origins

DragonFly got started after the then FreeBSD contributor Matthew Dillon was seized from his commit bit, due to technical disagreements about how SMP should be done in FreeBSD 5.x, he then proceeded to fork FreeBSD 4.8 and created DragonFly, While initially focusing on correcting the SMP code, have since became a general cleanup and simplification of all kernel subsystems, to be able to fit their place in a single system image clustering system, inventing LWKT (Light Weight Kernel Threads) and HAMMER and HAMMER2 along their way to help reach their clustering system goal.

Tips

loading video and audio drivers on boot

unlike FreeBSD, DragonFly doesn't automatically load drivers at boot you will need to add it to the /etc/rc.conf file with the syntax:

<module>_load="YES"

replacing <module> with your driver name (which can be find in /boot/kernel). for example to load the legacy intel driver i915 and the intel HD Audio driver snd_hda add this to /etc/rc.conf

# load kernel drivers
i915_load="YES"
snd_hda_load="YES"

Getting keyboard to work in X

If your keyboard isn't working in Xorg, then install xf86-input-evdev like this:

pkg install xf86-input-evdev

and add this to your /etc/sysctl.conf file:

# fix Xorg keyboard input
kern.evdev.rcpt_mask=6

Power Saving

To decrease power usage, add these options to /etc/sysctl.conf:

# power off devices not in use
hw.pci.do_power_nodriver=3
# allow system to switch to lower C-states
hw.acpi.cpu.cx_lowest=C3
# (not related) turn off the beep in the console
kern.sysbeep_enable=0