Category: Administration / Server

NMAP basic network scanning – overview over LAN
27.02.2018

What computers are online? What services/ports in what versions are online/open? over poorly or not so poorly documented LANs you can get an overview by using nmap. yum install nmap; # centos/redhat apt-get install nmap; # debian/ubuntu # get a […]

CENTOS7 – vnc server remote desktop setup howto screen sharing in 2018 – x11vnc error: socket: Address family not supported by protocol (97)
20.02.2018

UPDATED! checkout vnc section of: https://dwaves.org/2018/05/07/getting-started-with-raspberry-pi-2-model-b-v1-1-vs-odroid-xu4-vnc-display-0-and-1/ UPDATED AGAIN! if you have problems connecting and get the error message: „x11vnc error: socket: Address family not supported by protocol (97)“ then you probably have ipv6 disabled on the client. (and even if […]

CentOS7 setup virtualbox
07.02.2018

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

Docker
29.01.2018

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 or OpenVZ so […]

12.01.2018

When you reserve a new domain – and the registrar asks you for your (personal?) mail to be published in the whois database. You better give it a mail address designated for spam. I just received a spam letter at […]

amd arm intel cpus all got problems – Meltdown and Spectre – JavaScript could steal your Firefoxs Passwords
04.01.2018

update 2018-03-15: from C’t: new micro codes for intel iCPUs (2011 and onwoards) seem to fix Spectre v2 (CVE-2017-5715) 60minutes: https://www.heise.de/security/meldung/Spectre-Luecke-Intels-Microcode-Updates-fuer-Linux-und-Windows-3994347.html update: good overview and explanation of the situation: ARM also affected. The Meltdown + Spectre Vulnerabilities update: please checkout […]

Sidexis4 – 3d xray and kvm virtualization
23.12.2017

as addressed here, kvm allows GPU pass through to VM. Basically making it possible to run Sidexis4 client on a linux host. when connecting via RDP (Microsoft Remote Desktop) Sidexis complains about the Graphic card being not suitable… but starts […]

How to setup Dokuwiki – where is the login admin screen?
22.12.2017

per default there is no admin/login screen… until you run install.php here is the complete setup documentary… have fun. ssh into your server create subdirectory mkdir /web/root/dokuwiki wget https://download.dokuwiki.org/out/dokuwiki-c5525093cf2c4f47e2e5d2439fe13964.tgz; # download tar fxv dokuwiki-c5525093cf2c4f47e2e5d2439fe13964.tgz; # unpack depending on your rights […]

20.12.2017

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 […]

19.12.2017

tested on: hostnamectl Static hostname: DebianLaptop Icon name: computer-laptop Chassis: laptop Operating System: Debian GNU/Linux 8 (jessie) Kernel: Linux 3.16.0-4-686-pae Architecture: x86 i assume you have your laptop/pc LAN connected to a switch/router and your default network card is eth0. […]

Linux CentOS7 install mate and virtualbox guest additions
17.12.2017

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: […]

06.08.2017

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 […]

06.08.2017

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 […]

Howto install and setup File Sharing Server with GNU Linux
04.08.2017

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 […]

02.08.2017

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 […]

01.08.2017

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
31.07.2017

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
31.07.2017

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 […]

31.07.2017

sending a mail with fake „from:“ to existing.com telnet existing.com 25 Trying 78.46.249.71… Connected to existing.com. Escape character is ‚^]‘. 220 existing.com ESMTP Exim 4.84_2 Mon, 31 Jul 2017 11:41:29 +0200 EHLO SMTP.example.net 250-existing.com Hello hsi-kbw-5-158-158-169.hsi19.kabel-badenwuerttemberg.de [5.158.158.169] 250-SIZE 52428800 250-8BITMIME […]

28.07.2017

  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 […]

27.07.2017

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) […]