End-To-End-Encryption is nothing new. With messengers like Whatsapp or Telegram it’s again an issue. If E2E-Encryption means that nobody but the endpoints are able to encrypt the messages, then how is this feature implemented so seamlessly?

Perf is a profiler tool for Linux 2.6+ based systems that abstracts away CPU hardware differences in Linux performance measurements and presents a simple commandline interface. Perf is based on the perf_events interface exported by recent versions of the Linux kernel. This article demonstrates the perf tool through example runs.

Duplicity is a powerful backup-tool for encrypted incremental backups to a local or a remote storage. In this article I will show how to recover a state of a file from a specific time…

Sometimes we want to review the differences between the remote repository and the local one.

If you want to find out some informations about your BIOS or if your machine has a raid-controller, you can use the following command:

I wrote a simple webapp-stress-tool. Simulty is a very simple webapp-stress-tool. It reads random urls from a file and executes multiple get-requests simultaneously to them.

LXC-Containers are very useful. They are more leightweight than virtual machines and not as static as docker-containers. That’s why I like them especially for my server environments. In this article I will show a very basic setup of LXC-Containers on Debian Jessie.

Sometimes it is neccessary to filter packets based on their geo-ip location. Shorewall can make use of the xt_geoip-module for iptables. In this article I will explain how to setup this module on Debian.

I really like BTRFS, that’s why I write so much about it. But there are some issues with it. BTRFS is based on the copy-on-write principle but this can create some real troubles with virtualisation or databases. Therefore I will explain in this article how to disable cow.

It’s pretty comfortable to search and replace text in files using perl and regular expressions. Using one single command we can search, replace and create backups of all the files at once.