Home

New pages

Most visited

raspiBackup - How to backup your Raspberry

Details: Created: 18 June 2013; Last Updated: 23 June 2017; Hits: 34633

raspiBackup allows to create backups of a running Raspberry. No shutdown and manual intervention is required. Instead important services have to be stopped just before starting the backup and when the backup has finished they have to be started again. Any device which can be mounted on Linux can store the backup (USB disk, USB stick, nfs, samba, sshfs, ...). The common Linux backup tools dd, tar and rsync using hardlinks can be used to create the backup. Backups can be restored on any SD card. An external rootpartition will be included in the backup. NOOBS images are supported.

How to move a root partition of a Raspberry Pi to an external partition

Details: Created: 12 April 2016; Last Updated: 03 June 2017; Hits: 874

raspberry

There are various reasons (performance, space, ..) why you want to move your root partition from your Raspberry sd card to an external device like an USB disk or USB stick. You can do it manually or use a small script to achieve this.

raspiBackup - FAQ

Details: Created: 30 November 2015; Last Updated: 12 April 2017; Hits: 2295

raspiBackup - How to restore your backup

Details: Created: 02 March 2014; Last Updated: 26 March 2017; Hits: 7664

With raspiBackup you can create regular backups of your Raspberry. In addition you can restore a backup to any SD card. A new partition table is created on the target SD card and the backup data is restored on the partitions. If an external root filesystem was saved with raspiBackup this filesystem will also be restored to an external device.

Protect Raspberry Pi against internet attacks and disable attacks into the local network with a firewall using iptables

Details: Created: 01 November 2014; Last Updated: 19 February 2017; Hits: 2246

The Raspberry Pi is a nice system which is used a lot of time to provide server services to be accessible from worldwide. That's Owncloud, a HTTP server, seafile or other services..

A VPN is the right way to access the server in a secure way. But if you want to give a lot of people access there is no way other than to allow access direct from the internet. Usually you use a DMZ for this but that's a feature a normal home router doesn't have. But now you should protect the Raspberry from internet access as far as you can and also protect your home network from access from the pi server when an intruder managed to get access to the pi. But note: If an the intruder managed to get root access then the iptables firewall can be turned off very quickly. So it's very important to get SW updates on a regular base.

Following article describes how to configure an iptables firewall to protect it from unauthorized access from the internet and to protect a local home network to be attacked from the server - just in case.

SQL joins made easy

Details: Created: 05 November 2011; Last Updated: 24 July 2016; Hits: 2888

SQL is not very easy to learn, in particular joins of multiiple tables are difficult to understand at a first glance. On the next pages it's explained for sql beginners how SQL joins work. Venn diagrams are used to explain how the tables are combined. In addition sample tables with sample data and sample joins are used to explain in detail the query input data results. SQL files to create the sample data and execute the queries can be downloaded. The samples are for mySQL and DB2.

Docker in 5 minutes by example with a Wordpress- and MySQL-Installation

Details: Created: 21 February 2016; Last Updated: 24 July 2016; Hits: 1045

The german computer magazin c't periodical No 5 from 2/20/2016 has multiple interesting articles about docker and how to create a wordpress installation very fast. The following article explains how to install docker on Linux Mint 17.1 and summarizes the commands explained in c't about docker and how to setup a local wordpress via docker. Additional commands about docker are also explained in addition how to create your own nginx docker image. Other articles in the computer magazin explain in detail the way docker works and how to orchestrate containers.

Raspberry PI Trafficlight Sample Program written in Python with Threading

Details: Created: 19 December 2015; Last Updated: 24 July 2016; Hits: 1225

To learn to use threading in Python you have to have a concrete problem to solve. Just use Raspberry Pi to connet 6 LEDs and manage them via GIO. On the following pages I describe how to customize my sample program to simulate tarffic lights. You also find a video which shows the program in action and a download link for the sample program.

Calculate geolocation (Longitude and latitude) and local sunrise and sunset time

Details: Created: 13 May 2015; Last Updated: 13 June 2015; Hits: 1507

Add new comment

It's very useful if your Raspberry can trigger events based on time and sunset and sunrise. That's why I did some investigations on this and finaly found two APIs in the internet which allowed me to write a Python script to calculate these values very fast. gneadr found another interesting variant which I modified a bit. The location calculated is the place where the internetprovider offers the IP address to the client and which can be far away from the actual client location. In my case it's approx 30 km.

mySQL installation step by step

Details: Created: 11 November 2011; Last Updated: 10 October 2014; Hits: 855

If you want to use the SQL example files from this website and execute them on your system you have to setup a mySQL database on your system. It's quite easy and the following steps describe how to setup and configure mySQL on Linux Mint11. On other Linux distributions the way to install mySQL will be the only different step.