Generating an SSH key pair

ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/cantin/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/cantin/.ssh/id_rsa.
Your public key has been saved in /home/cantin/.ssh/id_rsa.pub.
The key fingerprint is:
f6:61:a8:27:35:cf:4c:6d:13:22:70:cf:4c:c8:a0:23 cantin@sodium

First Boot – Configuring your Pi

Right you have a Pi, and a power supply, and and its hooked up to some sort of monitor and TV and you’ve followed the instructions to format your SD card with Debian, its time to boot the little beauty and get it configure.

Pop in the SD card, insert the power supply and watch as the screen springs to life showing all sorts of operating system code. Nothing to worry about, watch it with awe as the OS boots and goes through its basic checks.

The first time the OS boots it starts with the following screen which is a program called raspy-config and allows you to configure the basic parameters of the operating system.

Its menu drive and easy to use with just a keyboard. No shinny shinny GUI here for you windows and mac users, this is hard code command line !!

First option displays some information about the tool

Press the cursor keys until <OK> turns red and the press OK, this takes you back to the previous screen.

Move to the next option which allows you to repartition the SD card to use all of the available memory rather than the 500M of the image you downloaded

The work will not take please until you reboot ( see below ), so as soon as you press OK it returns to the main menu

Next we set the keyboard. I use an old Mac keyboard, but you should search the list for the right version, the next menu then allows you to select more specific version of the keyboard

The next few options can be skipped through by selecting OK as they are more about configuring keys that you’ll use with Windowing system, but we are building a super computer and don’t need them

Again skip through this section

And this one…

Once you return to the main menu, the next option is to change the password for the default user ‘pi’

When you select this option, you’ll be prompted to enter a new password

After you have entered it and then reconfirmed it, it will confirm everything has been changed. You’ll need this password at the end of this section to log into the Pi

Next we set the memory usage. I tend to stick with the default option of using as much for the OS and the minimum for the graphics as we are doing super computer cool stuff not fancy windows stuff on this project

Next we set the overclocking options. Take note of the warning. If you are not comfortable with this process leave this option at default.

If you have a Rev 2 board then you can use the Turbo mode which runs the Pi at 1Ghz.

I’ll write a whole article about overclocking and the options for really binning your board later

Next we enable the SSH server. This will provide us a mechanism to log into each of the machines from your PC or Mac rather than attached a mouse and keyboard and monitor to each device.

Finally we select the boot option to not boot straight into X windows instead just the command line when the Pi starts.

You can easily start the windowing system with the command starts from the command line at any time once you are logged in

Finally select to reboot the Pi to finish the configuration

Select to restart and the system will reboot and you’ll see the text scroll past as before. However this time if you elected to extend the file system across the whole of the CD card above, then it will pause while it carries out this work.

This can take anything up to 5 mins for a 16GB card, so be patient, eventually the system will continue…..

Thats it, its booted and running, to login enter username pi and the password you entered during the password stage above

Next steps are to create a new user and install all the software to create an amazing super computer platform….

Raspberry Pi Super Computer Physical Build Stage

Time build the physical computer, which will become a 4+1 Node super computer. To get the cases to stack, I’ve wrapped them into pairs with a bit of electrical tape. Here is Raspberry1 and Raspberry2 stacked

And again giving me 2 pairs of 2 Pi’s, this time Raspberry3 and Raspberry4

Take 1 10/100M Switch….

Add 2, 2 node Pi stacks….

Next we add a new comer to this project, RaspberryPrime, this is the 5th node in the stack and will be the coordinator of the 4 worker nodes

All the Pi’s are now wired to the switch…

And Raspberry Prime is located on top of the stack ready to control Raspberry’s 1, 2, 3 and 4

Cool eh ?