Category: GNU-Linux


somtimes it is easier to land on the moon… than install a printer… [root@centos user]# hostnamectl Static hostname: centos.template Icon name: computer-desktop Chassis: desktop Operating System: CentOS Linux 7 (Core) CPE OS Name: cpe:/o:centos:centos:7 Kernel: Linux 4.15.1 Architecture: x86-64 Epson_Stylus_SX510W […]


… i never regret the learning curve of going Open Source. its not easier – but way more solid. order yourself a try without install boot stick today: if it does not boot – money back!

CentOS7 install ntfs support

one partly cloudy day i was trying to copy things via usb stick… it would not work. i realized: i haven’t used NTFS for a while 😀 yum install ntfs-3g fuse replug the stick. you don’t even have to restart […]


who is who? concepts: docker is written in Google Go by Docker Inc, SanFrancisco because it does not emulate any hardware – it is a linux container / sandbox or jail like Free BSD Jail or Solaris Zones. For example […]

linux bash bc – calculating with pi

bc is cool, but it can not access shell variables directly, but you can pass them with <<< also there is no „pi“ constant in bc that you could use in interactive mode. let one assume you would like to […]

gpg verify downloaded software – no public key

if you download software, you should verify that what you downloaded is not a altered file of a hacked server distributing trojan horses and keyloggers (malware). it seems for the gpg verification it is a 3 step process. 1. download […]


on intel / amd cpus/boards: use lm sensors: apt-get install lm-sensors; # install sensors-detect; # detect available temperature sensors, answer with YES usually # monitor cpu temp every second while true; do sensors|grep Core; sleep 1; clear; done; service kmod […]


it is pretty cool… a 32Bit Linux Host can run a 64Bit Linux guest. NICE 😉 i assume you have a working CentOS7 basic installation and are root. tested on/with: tested with: Host: Debian 8 Jessie and CentOS7 Operating System: […]

Thunderbird Icedove Reorder Accounts

first of all – thanks for this cool mail client 🙂 i really love icedove / thunderbird. A very cool feature that i am missing – it’s nice that imap can syn mail accounts – and i really love that […]

VirtualBox under LinuxDebian – Hang Hung VM on Starting Virtual Machine

this applies to: VirtualBox Version 5.1.8 r111374 (Qt5.3.2) hostnamectl Static hostname: DebianWorkstation Operating System: Debian GNU/Linux 8 (jessie) Kernel: Linux 3.16.0-4-686-pae Architecture: x86 the VMs hangs on startup with this screen: Solution: kill the vm then disable audio device… the […]


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 […]

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 […]


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 […]

CentOS7 Security Profiles and Software Security Flaws TopList

exploits in software toplist: 2017: All time: 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: manpage – dynamic linker – root@debian9:~# ldconfig -p 664 libs found in cache `/etc/‘ (libc6,x86-64) => /lib/x86_64-linux-gnu/ (libc6,x86-64) => /usr/lib/x86_64-linux-gnu/ […]


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 […]


Init Ram Disk filesystem – kind of mini OS in order to mount raid and start „the real /root os“. hostnamectl; # tested on Static hostname: debian9 Icon name: computer-vm Chassis: vm Machine ID: 532eabca552b4075a8679094397c8dba Boot ID: 15ee0b8e8a1e4d1eb1003c4630644091 Virtualization: microsoft […]


you should setup harddisk encryption during setup. to add an encrypted /home partition afterwards might be possible but a lot more effort. scroll very down if you want to know how to encrypt an usb sticks … needless to say […]


hostnamectl; # tested with Static hostname: debian9 Icon name: computer-vm Chassis: vm Machine ID: 532eabca552b4075a8679094397c8dba Boot ID: 56c17320171e4ca2aed93998357ce1d2 Virtualization: microsoft Operating System: Debian GNU/Linux 9 (stretch) Kernel: Linux 4.12.0cuztom Architecture: x86-64 apt-get install genisoimage genisoimage –help genisoimage -r -J -l […]