Author: Chewett

Backup a Raspberry Pi with Rsync

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

New website created

A slight deviation from my normal weekly posts to announce that the most recent update to chewett.co.uk has been uploaded! I have added a couple of pages including: Contact me page – A simple page with the easiest way contacting me Legal Stuff – Includes the software licence for code snippets on my blog and website

Veracrypt Error device-mapper: reload ioctl Error Fixed

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

Overview of the Raspberry Pi Cluster

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

Stacking Raspberry Pi’s

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

Powering a Raspberry Pi Cluster

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

Stacking multiple Raspberry Pi’s

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

Building a Raspberry Pi cluster

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

BIGINT Overflow Error Based SQL Injection

In MySQL 5.5+ you can abuse a new feature with BIGINT values. This involves a problem called integer rollover and your ability to run arbitrary SQL. The problem of integer rollover Integer rollover happens when a number is too big or small and is made bigger/smaller. In the case where the number is the highest

Why are PHP’s function names a mess?

I have always wondered this, its exceptionally hit and miss and there isnt any real standards. I recently found the reason on the internet Well, there were other factors in play there. htmlspecialchars was a very early function. Back when PHP had less than 100 functions and the function hashing mechanism was strlen(). In order to

Install Virtualbox guest additions on Fedora 21 XFCE

Installing via the normal route didn’t work and meant I couldn’t easily resize the screen. Doing the below allowed me to use the resize easily. Install rpmfusion on fedora run `sudo yum install akmod-VirtualBox VirtualBox-guest` run `cd /usr/src/akmods` run `sudo rpm -ivh VirtualBox-*.rpm` Once this was installed, rebooting will give you access to shared folders and fullscreen mode