Category: General / Allgemein

NGINX as HTTP proxy – vhosts and SSL for Tomcat

Secure Socket Layer (SSL) is a protocol that provides security for communications between client and server by implementing encrypted data and certificate-based authentication. Technically, the term „SSL“ now refers to the Transport Layer Security (TLS) protocol, which is based on […]

CentOS7 setup virtualbox

headless server: tested: 2018-10-17 on CentOS Linux 7.5 (Core) wget rpm –import oracle_vbox.asc cd /etc/yum.repos.d/ wget yum update yum search virtualbox yum install VirtualBox-5.2.x86_64 # if you want/need usb 3.0 extension package wget VBoxManage extpack install Oracle_VM_VirtualBox_Extension_Pack-5.2.20.vbox-extpack […]


Gold – cash – electrons – magnetic fields really? Is that how mankind pays its bills? At ever higher risks of things getting hacked or stolen. Imho this is not making life easier – it is making it more complicared […]

Who is THE Urban Penguin?

Andrew Mallett also on twitter apparently… 😀 pretty complete video series on LPIC1 FOR FREE ONLINE ON YOUTUBE 🙂 GOOD JOB MR MALLETT! 🙂 THANKS! LPIC2 not so much… you will have to pay for it 🙂 Andrew is an […]


nginx can be used as webserver, web-proxy and even mail-proxy. „Apache ist aufgrund seiner Architektur und Arbeitsweise doch eher der Traktor unter den Webservern.“ X-D (src) let me try to translate: „Apache is due to its architecture and functioning rather […]

webserver software marketshare – NetCraft – Web Internet stats statistics – growth number of sites – total number of websites – internet stats statistics

according to apache(2 i guess) is still the dominant webserver on the internet with a market share of 50%. src: according to it is „only“ 40% market share for the apache(2) webserver. also most sites are running […]


btrfs is used by SUSE12 for the /root partition – where it is doing daily snapshots of the installed OS. It has more functionality built-in than just storing files. This article wants to take btrfs for a test-drive. Video Tutorials: […]


Elon Musk: 2018: „Ai is far more dangerous than nukes“ and should be regulated. „We have to ensure that the advent of digital super intelligence is symbiotic with mankind“ teaching Artificial Intelligence Laboratory, Department of Informatics, University of Zurich […]


to be honest… i find all of those meassurement tools too complicated to install. they probably all have their validity – but why not simply do it like this: given that you have a webserver installed and the web-root is […]

about – x11 display server – display or login manager – window manager

The X11 Window System Developer(s) X.Org Foundation  Initial release 6 April 2004; 13 years ago[1] Stable release 1.19.3 / 15 March 2017; 2 months ago[2] Repository, git://, git:// Written in C Operating system Cross-platform Size 3.7 MiB[3] Available in English Type Display […]

top10 most used mail servers – segfault exim4

a hacked e-mail account is a catastrophe – look at Hillary. telnet 25; # a simple telnet tells you that this server is running Trying… Connected to Escape character is ‚^]‘. 220 ESMTP Exim 4.XX_X Tue, […]


passwd -l maria; # disables account maria passwd: password expiry information changed. grep maria /etc/shadow maria:!$6$w9DaelrP$/tJiXC2PU0B.XOupP0sFTySis5VfkMwv0DnoFy3.d.nC8gXJU.DSbU0Uryyex40P67keCFoQuxEjZ8RD9kDGU0:17325:0:99999:7::: passwd -u maria; # enable account maria passwd: password expiry information changed. /etc/passwd grep /bin/bash /etc/passwd; # output all interactive user accounts that use […]

gpg cheat sheed – encrypting files with gpg

Warning! while gpg is very likely sound and solid encryption – what is far more likely to be compromised is YOUR HARDWARE – every network card – wifi card – usb UMTS G3 modem – PCI-Card – contains enough RAM […]

cool stuff you can do with ssh

i assume you have setup public-private-key-authentication and tested its workings and tightened security to only allow public-private key auth of specific non-root users. run local scripts remotely You can run local scripts remotely by executing bash on the remote system […]


looks different in every distro… Debian8 root@debian:~# uname -a; # tested on Linux debian 3.16.0-4-686-pae #1 SMP Debian 3.16.43-2 (2017-04-30) i686 GNU/Linux root@debian:~# ll /etc/X11/ total 72K drwxr-xr-x 2 root root 4.0K Jun 2 15:39 app-defaults -rw-r–r– 1 root root […]