Friday, December 12, 2014

Ceph Pi - Misc

So while writing this series, I am trying out some things.  This is going to be a list of those.  This article may get updated in the future with extra steps.

Slimming down Raspbian


I am not going to be using a GUI (connected to a display) on my Raspberry Pi.  So I decided to slim down by Rasbian install. 

Edit:
As I was building the Banna Pi version of this project, I discovered a better, faster way to do this
  apt-get remove  --auto-remove --purge libx11-.*
This essentially grabs everything that is dependent on libx11 and nukes it.  The box does reboot afterwards, and presents a very barebones server.  You will likely have to reinstall some packages again as needed.

The first thig I did was to get a list of all the packages installed
 dpkg-query -l  

Looking through the list, I chose the following packages to blow away

 sudo apt-get purge xserver-common xserver-xorg xserver-xorg-core x11-common xauth libx11-6 libgtk-3-0 libgnome-desktop-3-2 libgnome-desktop-3-4  
 sudo apt-get autoremove  

This gets rids of the vast majority of GUI stuff that we won't need.  The reason you want to do this as early as possible is to save a bunch of time as you update your system.

Installing a NetFlow Generator

As we try to understand how our network functions, few tools give us as much information as a good NetFlow trace.  While I can rely on SevOne to give me fast quality analysis of NetFlow data, I still need to get it from somewhere.  My Comcast router does not seem to be capable of generating it, and if I was inclined to use an enterprise scale generator like the APA, my NetGear switch does not have a SPAN port.  So I am looking to install a light weight NetFlow generator straight on the raspberry pis.

 sudo apt-get install softflowd  

go ahead and edit /etc/default/softflowd 
 sudo vi /etc/default/softflowd  


change the INTERFACES line to "any" and in the options tag the ip of your netflow collector (if you don't have one - SevOne has a a great one :)
 OPTIONS="-n 10.0.0.10:9996"