This post builds on my previous posts in the Raspberry Pi Cluster series by adding the ability to receive data from the master. In this update, I will be adding a way for the slave to request data and have it returned by the master.
This post builds on my previous posts in the Raspberry Pi Cluster series by changing how the slave sends messages. From now on the slave will send useful information about the system to the master. The master will also be configured to receive messages of many types.
This post builds on my previous posts in the Raspberry Pi Cluster series by changing the format of the data I send. In this tutorial I am now sending data as JSON to allow a richer set of messages to be sent.
This post builds on the third step to create a Raspberry Pi Cluster Node to store our configuration settings in a config file. Here we move all the configuration settings in our script into a useful .cfg file using the python ConfigParser.
I am going to upgrade our previous Raspberry Pi backup script that previously used Secure Copy to one that uses rsync. The primary reason for this is that rsync will only copy new or changed files over. This post goes through the reasons why you might want to use rsync instead of scp when performing a
This post builds on the second step to create a Raspberry Pi Cluster Node to create a hello world application across two different scripts. Here we will create a socket connection between the two and use it to send a message to the master.
Today I will be improving the basic script used to backup my Raspberry Pi’s so that it compresses the files after they have been copied. This will allow me to store several backups instead of having a single copy stored on my computer. This assumes you have followed the first tutorial to create a Raspberry
This post describes how you can upgrade Raspbian Jessie, version 8, to Raspbian Stretch, version 9. Raspbian Stretch was recently released and while they recommend installing from fresh you are able to upgrade the versions. Here I follow the steps of upgrading the Raspberry Pi’s in my cluster including some of the common problems that
This post walks you through the process of installing the Raspberry Pi OS, Raspbian, with VirtualBox. I am going to use this at times to test my software running on the OS that the Raspberry Pi Cluster runs.
To set up a Raspberry Pi node I will follow a specific set of steps so that every Pi is set up similarly. For the initial deployment I will follow this once and then clone the SD Card multiple times. If at a later date more are added I will use this guide to follow
For my cluster project I will add a new user to each Raspberry Pi. This is so the user I use for all other systems will be the same on the Raspberry Pi’s. This post describes how to add another user to Raspbian OS.
I will be testing the performance of each Raspberry Pi version in my cluster. This is to determine what each one is best suited to running. To do this I need a similar set of tests to run for each and compare them. Ideally the tests will also be runnable on other embedded Linux devices
Since the first Raspberry Pi was released in 2012 there have been a number of changes to their design. Since I plan to include a number of different models in my cluster I will review and test each model to find its weakness and strengths.
To set up my cluster I want to create single SD card image then run this same image on multiple Pi’s. This means I wont need to set up each Raspberry Pi at a time. One of the ways you can do this is by taking an image of the raspberry Pi then flashing that
The Raspberry Pi foundation have recently updated their Raspbian image. This brings bugfixes and upgrades to the Raspberry Pi. In this blogpost I share how you can run a command on your Raspberry Pi without logging in (this is mostly true although you still do “log in” just not in the typical way). This includes
When trying to mount an encrypted drive using Veracrypt I encountered this error: chewett@bunker-master2:/mnt$ veracrypt /dev/sdc1 gen500 Enter password for /dev/sdc1: Enter PIM for /dev/sdc1: Enter keyfile [none]: Protect hidden volume (if any)? (y=Yes/n=No) [No]: Error: device-mapper: reload ioctl on veracrypt2_0 failed: No such file or directory I did some research and found out that
I was setting up a new install of Raspbian Pixel and found I couldn’t login to the Raspberry Pi. It was giving me an error: chewett@bunker-master:~$ ssh pi@raspberrypi ssh: connect to host raspberrypi port 22: Connection refused It turns out that recently the Raspberry Pi Foundation have changed the default setting for SSH and disabled
Now I have the power supply and built the stacking system I can show off the clusters initial state. Every Raspberry Pi in the cluster Here are the 7 initial Pi’s that are to become part of the cluster. Each have been given a codename to designate its position in the cluster. The Raspberry Pi designed “M” will be
If you are getting “Read-only file system” on your Raspberry Pi when mounting drives there is a simple fix. chewett@bunker-master2:/mnt/wd500$ touch test.txt touch: cannot touch ‘test.txt’: Read-only file system I noticed this happening when I tried to mount and work on my external hard drive. This is formatted with the NTFS filesystem. I did some
This post is a review of the “Light Intensity Sensor Module 5528 Photo Resistor” and includes code and images to use the sensor. There are a couple variants of this light sensor sold by different companies but all have similar components and designs. This model is sold by HiLetgo CN and is available on amazon (link below).
One of the objectives for the Raspberry Pi cluster is to manage a number of servers including syncing their contents and backing up databases. The data included may contain personal information so they are always backed up to an encrypted drive. This means I need to be able to access the encrypted content on the Raspberry
The stackable Raspberry Pi case purchased allows stacking Raspberry Pi B+ and Raspberry Pi 2/3 but I was planning to modify this to stack older Pi’s. Stacking the Raspberry Pi (256 MB) The original Raspberry Pi does not have any mounting points. This makes it quite hard to stack using my chosen stacking solution. Therefore for the time
To access some of the lower level aspects of the Raspberry Pi’s config you can use the built in command vcgencmd. This is a useful on the command line but to easily access it in a program you need to parse the output. I am planning to use this command to store data like the
I want to be able to access my Raspberry Pi Cluster and log onto any node without entering a password. To do this I can set up as passwordless SSH key. Generating a SSH Key To generate a SSH key you can use the command ssh-keygen. Once you have ran this you will get the
The Raspberry Pi doesn’t come with its own power supply so you need to decide how to power it. The recommendation from the Raspberry Pi website is that they have “found that purchasing a 2.5A power supply from a reputable retailer will provide you with ample power to run your Raspberry Pi”. After doing some research
Something I want to do with my Raspberry Pi Cluster is mount a hard drive and share it like a windows share. To do this I am going to set up Samba on a Raspberry Pi. Installing the required packages To run samba as a service we need to install a couple packages. Running the
Here I suggest some recommended steps to install Raspbian on top of their install guide. Choosing an OS for the Raspberry Pi One of the main ways to install a Raspberry Pi OS is to download a disk image called NOOBS. This lets you choose to easily install a number of different OS’s. If you want to
For the Raspberry Pi cluster I wanted to make sure that they are neatly stored to keep them easy to reach. Why nicely storing them is important Each Raspberry Pi requires a power and network cable. When using a single raspberry pi the cables are not an issue but I am planning to use five as a baseline
Today’s blog marks the official start of my Raspberry Pi cluster project. Here I will be documenting the process of assembling, building, and running a small cluster. This blog will include both code snippets, hardware diagrams and the results of various projects using the cluster. Aims of the project The Raspberry Pi cluster will be looking into distributed