OpenBSD Journal

R2D2, The Force, and OpenBSD

Contributed by jose on from the amusing dept.

As seen on :

"R2D2PC is a completely fanless router running OpenBSD 3.4-stable. It serves very well as firewall, router, mp3 player, web and file server. To guarantee absolute noiseless operation the complete OS is placed on a 512mb compact flash card. I've used a boot floppy for the OpenBSD installation and downloaded the necessary packages via FTP. The mechanical hard drive is mounted as /home. It starts spinning only when personal data is accessed or when the system gets upgraded from sources. Httpd, smtpd and all other services are completely independent from the mechanical hard drive. A mfs (memory file system) RAM disk makes it possible to play many mp3 files without the need of a spinning hard drive. On average (low CPU usage) the router consumes less than 20W per hour."

Now that's an interesting use of OpenBSD.

(Comments are closed)

  1. By hovil () on

    Currently I have a grunty box that sounds like a helicopter is hovering outside my window hooked up to my amp, while playing music louder is always an option, I'd rather move el-grunt-o to another room and stream music to a quiet machine such as this; though in a far less conspicuous case.

  2. By Anonymous Coward () on

    YAY for OpenBSD :) I personally like the idea of giving computers a pleasing look...instead of the boring old boxen. Just wish I had the money and imagination to impliment something like that. On a slightly off-topic note about noise... has anyone used one of those Tip Magnetic Driven fans? According to most reviews they perfome extremely well...but I haven't read many real-world experiences yet. Anyone have any?

    1. By Michael () on

      The magnetic fans are just as good as the stock fans. Keep in mind that I haven't done any sort of overclocking.

      One thing that worries me a little bit is the fact that if the fan breaks and stops spinning, I won't be able to hear the noise difference as my CPU bakes.

    2. By FormerRetailOwner () on

      I owned half a retail computer store until recently, and we had a lot of the Vantec Aeroflow heatsinks die on us (more than 20%). I use a Coolermaster Aero 7+, and if you turn the speed down, it can be an extremely quiet, yet effective, cooler.

  3. By Anonymous Coward () on

    Awesome! I'm looking into a way of doing something similar myself with Compaq Flash or SanDisk and either mini-itx or some embedded systems.

    A few links of interest to some people:

    Of course also:

    And as mostly everyone knows:
    and others...

    What I'd like to do though also is be able to make a small version of OpenBSD (FW/Router/IKE) only version in as little space as possible. Either on Flash/SanDisk media, CDROM with MFS (preferably) or HD.

    Anyone have such experience with; advice and/or pointers on how or where to start on such a thing other than from the links I've pasted?


    1. By jose () on

      i have a small 4.7 MB network access device (NAT, router, etc ...) which i documented here:

      uses nsh, an openbsd 3.3 kernel, and a very simple configuration engine. should be trivial to add IKE to it. now that i have more time, i should use my second soekris for more testing ...

    2. By Anonymous Coward () on

      Have a look at - pure OpenBSD OS, no moving parts, config menu. We use it happily for firewalling, NAT, DHCP, isakmpd, etc.

  4. By Michael Sullenszino () no spam at sullenszino org on mailto:no spam at sullenszino org

    I have been making little appliance firewalls with ScanDisks (128 and 256MB) for almost two years now. You can optionally add a RAID frame mirrored set if you want to do email gateway spam-virus-filtering, SQUID content filtering or even IMAP. The OpenBSD install process makes it easy to create your own custom distribution! I put it in a micro-destop and it works great! I probably have almost 30 deployed.

    1. By Anonymous Coward () on

      Any documentation on the steps you've taken to do something like this? Sounds awesome!

  5. By Anonymous Coward () on

    Most compact flash cards aren't too durable when it comes to much writing. Depending on the configuration there might be much writing done (log files for example!)

    btw, what is "20 Watt per hour"? Either it's "20 Watt" or it's "20 Watt hours per hour" :)


    1. By jose () on

      yep. in my soekris install, i don't log locally, and anything else that's volitile goes in a memory filesystem (man mount_mfs). the CF card itself is run read-only, and is only written to at build time. everything is dynamically constructed otherwise ...

      and of course some CF cards work better than others ...

    2. By djm () on

      My Soekris loads a ramdisk kernel off flash and doesn't touch it after that (the ramdisk kernel is built with a modified version of flashboot ). Syslog is directed to another host and also stored in a local memory buffer (see my modified syslogd here ).

    3. By Anonymous Coward () on

      20 Whatt per hour? ;)

    4. By Anonymous Coward () on

      Work is the product of a force and a displacement. it is measure in Joules, and 1 Joule is the work done by a force of 1 newton moving a body through a distance of 1 meter.

      Energy is the capacity of a body to do work. Energy has the same units as work, and, by definition, 1 Watt-second = 1 Joule. And 1 kWh = 3.6E6 Joules.

      Power is the time rate at which work is done. By definition, 1 Watt = 1 Joule/second.


      "20 Watts" is a measure of power.
      "20 Watts/hour" is meaningless.
      "20 Watt-hours/hour" is also meaningless.

      What the author probably meant was the standard, but slightly ambiguous, usage for Energy that we see on all of our appliances. 20 watts.

      The actual Energy consumed (Joules, or equivalent) is probably 20 watt-hours. Not bad - less than a standard lightbulb, and only a bit more than the flourescent models.


      1. By Anonymous Coward () on

        > "20 Watts/hour" is meaningless.

        Actually, that would be the acceleration of power consumption, analogous to m/(s*s) which is the standard SI-unit for acceleration.

        If this is really what's meant, I suggest sacrificing the uptime and powercycling it once a day. :)

      2. By James Herbert () on

        > "20 Watt-hours/hour" is also meaningless.


        A watt-hour is a measure of energy, one-thousandth of a kWh, which I imagine is what your electricity company measures your consumption in.

        So, if you use 1 Wh (watt-hour) of energy in one hour, that's one watt average.

        So, if you use 20 Wh in one hour, that's 20 W on average. So it's not meaningless at all.


      3. By RC () on

        > Not bad - less than a standard lightbulb, and
        > only a bit more than the flourescent models.

        Well, 20w is good of course (not incredible in the slightest), but comparisons to lightbulbs aren't... I don't think I have a single computer around that uses more than 100W normally. Of course, the peak goes above that at times, but that is still less than a very common lightbulb.

        Incidentally, power consumption would be even less if using an old notebook. I have one, but with only one PCMCIA slot, and no built-in ethernet, it wouldn't make a very good router, until OpenBSD supports a Parallel-Port ethernet device of some kind. Now, I use an old 180MHz PentiumPro underclocked to about half it's clock speed, plus an always-on hard drive, and with that less-conservative setup, I'm only using about 35 watts.

  6. By larry lurex () on

    hey, we're using 3 obsd vpn-routers on 256-mb flash cards for 2 months without any trouble. all we need is to perform remote logging due to keep free space on cards ;-)

  7. By RC () on

    > The mechanical hard drive is mounted as /home. It
    > starts spinning only when personal data is accessed

    Can anyone explain how this is done? I just checked, and still in 3.4, when a hard drive is spun-down with atactl (and it happened when spun-down by the bios as well) it almost immediately spins up again. So, how is the hard drive able to stop spinning for any ammount of time in this setup?

    1. By Andreas Bartelt () on

      There's an option in the BIOS "HDD power down" - I've set it to 5 minutes. After 5 Minutes (with no access) the HDD turns off reliably. I don't see where's the problem.

  8. By Andreas Bartelt () on

    I've added new photos of R2D2PC to the gallery section at .

    I'm going to add more content to this website soon.

  9. By Andreas Bartelt () on

    I've added new photos of R2D2PC to the gallery section at .

    I'm going to add more content to this website soon.


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