… is a horrible hard exam. check out the (probably a little outdated) example questions below – to get a taste what to expect. according to PassLeader NO more recent braindumps are available… (201-400 yes 201-450 no) at the time […]


ome observers might well believe that the kernel has accumulated plenty of special-purpose virtual filesystems. Even so, 2.6.14 will include yet another one: securityfs. This filesystem is meant to be used by security modules, some of which were otherwise creating […]


the mail system is a very broken and corrupted system. sending-addresses can be forged – spam from all over the world is flooding the mailboxes – viruses get attached… nobody trusts attachments anymore. it’s a completely newly C++ developed mailserver […]


exim is one of the most used MTAs on mail-enabled servers on the internet and default on Debian/Ubuntu(?). Original author(s) Philip Hazel (started 1995) Developer(s) The Exim Maintainers Thus you can expect hackers, crackers and NSA to target it. Exim […]

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 […]

Howto install and setup File Sharing Server with GNU Linux

ext3+gnu_linux+samba = fast and reliable fileserver. WARNING! Security problems Versions from Version 3.5.0 to 4.6.4 (recent in May 2017 ) are affected and need to be patched! patches are available from: https://www.samba.org/samba/patches/ Unfortunately EVEN Debian9 (!!!! GUYS FIX THAT FAST […]


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 […]


I believe since you do not know the file name/process id, you could specify user name option as below. lsof -r 2 -u username The „-r 2“ option puts lsof in repeat mode, with updates every 2 seconds. (Ctrl -c […]

compiling squid http proxy from source

checkout what is the latest version: ftp://ftp.cuhk.edu.hk/pub/packages/info-systems/www/squid/ probably this is more recent: https://github.com/squid-cache/squid you could also try git clone https://github.com/squid-cache/squid.git and compile with the git source tree… let me know if it worked. hostnamectl; # tested on [root@CentosMaster squid-4.0.21]# hostnamectl […]

debian 9 stretch – howto setup docker container software

What is docker? (src) Docker is the world’s leading software container platform. Developers use Docker to eliminate “works on my machine” problems when collaborating on code with co-workers. Operators use Docker to run and manage apps side-by-side in isolated containers […]


sending a mail with fake „from:“ to dwaves.de telnet dwaves.de 25 Trying… Connected to dwaves.de. Escape character is ‚^]‘. 220 dwaves.de ESMTP Exim 4.84_2 Mon, 31 Jul 2017 11:41:29 +0200 EHLO SMTP.example.net 250-dwaves.de Hello hsi-kbw-5-158-158-169.hsi19.kabel-badenwuerttemberg.de [] 250-SIZE 52428800 250-8BITMIME […]


  i did just some basic testing… and managed to compile the php7.3 binary – but the make install failed. it would help to have multiple cores… hostnamectl; # tested with Static hostname: CentosSlave Icon name: computer-vm Chassis: vm Operating […]


i really don’t know why this is not a one-liner… it would save time and electricity and cause less searchengine-request. yum install epel-release yum install htop


in general: social competence demands to first praise then critizise – no matter what – nobody is perfect or god. praise: Thanks for this massively cool webserver software – that can do so many things (vhosts and .htaccess and php) […]

CentOS Redhat – compile Apache2 from source

i tried to compile under debian…. but it’s way more compli cated. also: you probably do not need all the packages stated here… but i did not have the time to sort those out sorry for that. feel free to […]

CentOS7 replaced firewall iptables with firewalld

no iptables no more – some things change faster than you can say „beneune„… check if it is up and running: systemctl list-unit-files|grep firewall firewalld.service enabled open a port, permanently: firewall-cmd –zone=public –add-port=80/tcp –permanent firewall-cmd –reload „The former firewall model […]

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

according to https://w3techs.com/technologies/overview/web_server/all apache(2 i guess) is still the dominant webserver on the internet with a market share of 50%. src: https://trends.builtwith.com/web-server according to builtwith.com it is „only“ 40% market share for the apache(2) webserver. also most sites are running […]

CentOS7 Security Profiles and Software Security Flaws TopList

exploits in software toplist: 2017: https://www.cvedetails.com/top-50-products.php?year=2017 All time: https://www.cvedetails.com/top-50-products.php That is why the Unix Philosophy of small, modular and beautiful matters … maybe that’s why Mr Stallmann prefers Microkernels… but well let’s be happy there is an alternative kernel to […]


the strangest thing about mtr is probably that it seems to work only with a desktop-terminal. not an ssh-terminal 😀 What is MTR? mtr combines the functionality of the ‚traceroute‘ and ‚ping‘ programs in a single network diagnostic tool. As […]


-p, –print-cache Print the lists of directories and candidate libraries stored in the current cache. manpage: ldconfig.man.txt manpage – dynamic linker – ld.so.man.txt root@debian9:~# ldconfig -p 664 libs found in cache `/etc/ld.so.cache‘ libz.so.1 (libc6,x86-64) => /lib/x86_64-linux-gnu/libz.so.1 libz.so (libc6,x86-64) => /usr/lib/x86_64-linux-gnu/libz.so […]


display ip and ip only of the host computer the script is running on. ifconfig eth0|grep inet| awk ‚{print $2}‘ | cut -d: -f2 root@debian9:~# IP=$(ifconfig eth0|grep inet| awk ‚{print $2}‘ | cut -d: -f2); echo $IP;


The Enterprise Volume Management System (EVMS) Project has the goal of providing unparalleled flexibility and extensibility in managing storage. It represents a new approach to logical volume management for Linux. The architecture introduces a plug-in model that allows for easy […]