Category: RedHat / CentOS

apt yum exclude package from update upgrade

maybe you want to run your own version of the kernel and you will have to prevent during an automatic update that this kernel will get „replaced“. same goes with firefox, thunderbird and LibreOffice yum and apt might not install […]

CENTOS7 – vnc server remote desktop setup howto screen sharing in 2018

UPDATED! it is wise to, monitor all logs while you are trying to get vnc server working… it can reveal a lot what is going on and wrong. forget about Xvnc and tigervnc… x11vnc is probably what you want: […]


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 […]

CentOS7 setup virtualbox

1. 2. checkout what is the latest version of VirtualBox for your System: su; # become root mkdir /software; cd /software; wget rpm -i VirtualBox-5.2-5.2.6_120293_el7-1.x86_64.rpm; # install usermod -a -G vboxusers YourDefaultNonRootUser; # add DefaultNonRootUser to group […]

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 […]


yum install kbd; # is needed ll /lib/kbd/keymaps/xkb/ | grep de-; # find all available germany keymap layouts localectl list-keymaps; # alternatively loadkeys de; # load keyboard layout localectl set-keymap de; # permanently change keyboard layout

compiling squid http proxy from source

checkout what is the latest version: probably this is more recent: you could also try git clone and compile with the git source tree… let me know if it worked. hostnamectl; # tested on [root@CentosMaster squid-4.0.21]# hostnamectl […]


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

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 […]

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 […]


strace from the manpage. trace system calls and signals In the simplest case strace runs the specified command until it exits. It intercepts and records the system calls which are called by a process and the signals which are […]

Linux Kernel – Security Updates

latest kernel related security problems can be found here… -> newsletter subsribe: also


debian has „codenames“ for it’s releases… i always get confused which codename is what release number. with those commands you can easily identify both. hostnamectl seems to be the cross-distribution solution for that. user@suse12:~> hostnamectl Static hostname: suse12.domain Transient hostname: […]

system logging – log files – rsyslog rsyslogd

TOS-based systems (Atari ST) used a row of bombs to indicate a critical system error. Number of bombs displayed revealed information about the error. The error (also called an exception) is reported by the Motorola 68000 microprocessor. The very first […]


file access modify creation time will always be in UTC format. In which time offset is +hours or -hours from Longitude: 0° (Prime Meridian) Prime meridian (Greenbich) GPS: 0° 00′ 05.3101″ W Other names: Z / Zulu Time Zone Time […]


What is yum? yum is used under CentOS7, Fedora, RedHat RHEL, Oracle). It’s written in python and it stands for “Yellowdog Updater, Modified”, as it was originally called “yup”, the package manager for Yellow Dog Linux. In addition to rpm […]


there are plenty 😀 debian8.8 uname -a; # tested with Linux debian 3.16.0-4-686-pae #1 SMP Debian 3.16.43-2 (2017-04-30) i686 GNU/Linux find / -type d -iname bin /bin /usr/local/bin /usr/bin /usr/share/doc/libintl-perl/examples/simplecal/bin /usr/lib/klibc/bin suse12 uname -a; # tested with Linux suse 4.4.21-69-default […]


rpm is a powerful Package Manager for Red Hat, Suse and Fedora Linux. It can be used to build, install, query, verify, update, and remove/erase individual software packages. A Package consists of an archive of files, and package information, including […]


su; # become root yum install kernel-devel # get kernel source # kernel sources will be copied to /usr/src/kernels/3.10.0-514.16.1.el7.x86_64/ # there is a broken softlink in # /usr/src/kernels/3.10.0-514.el7.x86_64 # -> # /usr/src/kernels/3.10.0-514.16.1.el7.x86_64/ # which you will have to fix like […]

linux CentOS7 – install MATE Gnome2 based Desktop

yum install epel-release yum groupinstall „X Window system“ yum groupinstall „MATE Desktop“ systemctl isolate; # Tell your systemd to start the per default unlink /etc/systemd/system/; ln -s /usr/lib/systemd/system/ /etc/systemd/system/; reboot; you should get a grafical login prompt now […]