07 February 2014

Cumulus Networks  is a new entrant in the network gear space. What separates them from other players is that they are not selling hardware but their own network focused Linux distribution called Cumulus Linux. Basically you buy a switch from one of their resellers or ODMs then pay Cumulus a yearly support license. There are a number of interesting things you can do like run your own code on the switch as well as use common Linux commands to configure the switch e.g. brctl, ports are exposed as Linux network interfaces etc.

One of the first things we ended up doing is installing Ganglia agent so that we can monitor what’s going on on the switch. Cumulus switch we had was running a PowerPC based control plane so that made things a bit tricky since we couldn’t use any of the amd64 built packages. One way to build PowerPC packages would be to get an old PowerPC based Mac and install Linux on it. Unfortunately that seemed like a lot of work and overkill. I realized we could just use Qemu which is an Open Source machine emulator so I could run PowerPC machine on my own laptop :-). Quickest way to get up and running is as follows.

On Ubuntu you will need to install following packages

apt-get install qemu-system-ppc openbios-ppc qemu-utils

Warning: Under at least Ubuntu 13.10 openbios-ppc doesn’t seem to work well. If you get a blank yellow screen after you start the install you will need to get openbios from other places e.g. https://github.com/qemu/qemu/tree/master/pc-bios

Once you get those you will need to download Debian Squeeze for PowerPC. You will need to download

  • vmlinux

  • initrd.gz



as well as the netboot image e.g.


Reason why you need initrd.gz and vmlinux is that if you try to do an install straight off the CD-ROM your install will hang here

Power PC install QEMU

Once you have those pieces initiate the install with

qemu-img create -f qcow2 squeeze-powerpc.img 10G
sudo qemu-system-ppc -m 256 -kernel vmlinux \
 -cdrom debian-6.0.8-powerpc-netinst.iso \
          -initrd initrd.gz -hda squeeze-powerpc.img -boot d -append "root=/dev/ram" \
          -net nic,macaddr=00:16:3e:00:00:02 -net tap

Now follow the installation process as you would if you were installing Debian or Ubuntu from scratch. When you are done with the install shut down the emulator. Now to invoke your PowerPC emulator execute

sudo qemu-system-ppc -m 256 -hda squeeze-powerpc.img  \
           -net nic,macaddr=00:16:3e:00:00:02 -net tap

Congratulations you are done. What you end up with is this

root@debian:~# cat /proc/cpuinfo 
processor    : 0
cpu        : 740/750
temperature     : 62-64 C (uncalibrated)
revision    : 3.1 (pvr 0008 0301)
bogomips    : 33.14
timebase    : 16570400
platform    : PowerMac
model        : Power Macintosh
machine        : Power Macintosh
motherboard    : AAPL,PowerMac G3 MacRISC
detected as    : 49 (PowerMac G3 (Silk))
pmac flags    : 00000000
pmac-generation    : OldWorld
Memory        : 256 MB