[Hardware] ASUS TUF GAMING B550M-PLUS and RTL8125B Realtek

Just switched some hardware parts in my main PC:

I moved from Intel to an AMD build. I kept my boot disk with Linux Mint 20 and everything was running out of the box, except there was no ethernet connection available. The RTL8125B Realtek network card is not yet supported on a Kernel < 5.9. Since I’m running Kernel 5.6.14, I had to manual install it.

Go to: https://www.realtek.com/en/component/zoo/category/network-interface-controllers-10-100-1000m-gigabit-ethernet-pci-express-software

Download the “2.5G Ethernet LINUX driver r8125 for kernel up to 5.6”, untar and follow the installation instructions from the README. In fact you only have to run

sudo ./autorun.sh
#check with
lsmod | grep r8125
ifconfig -a

[SAP] Install SAP Gui for Java 7.50 on Linux Mint 20


First have a look at the Requirements and FAQ.
Find the download link in the SAP Support Portal here. You will need a valid S-User and download permissions.

If you are not able to download the installer via Support Portal, there is a little workaround. Both, the installer for SAP Gui for Windows and SAP Gui for Java are also delivered with the AS ABAP 752 SP04, developer edition:

“The actual download (in the form of several .rar files), along with more information is available from the SAP Community Trials and Downloads page. Search for “7.52 SP04″ for convenience.”

You will have to download all 11 .rar files (about 14,6GB). When unziping, you’ll find a folder called client (about 1,2GB) containing both installers.


Since SAP Gui 7.50 Rev 5, Oracles JDKs is not necessary to run SAP Gui for Java, instead you are able to use OpenJDK. Read more about it here. And since version 7.50 Rev 8 the installer includes SapMachine and OpenJFX. Read more about it here. In this case, you don’t even have to install OpenJKD and OpenJFX by yourself and don’t have specify the module path, because it comes containerized within the SAP Gui.
So better first check the version of your downloaded gui. I’ve got SAP Gui 750 rev 5 within the AS ABAP 752 SP04. So let’s install openJDK & openJFX.

sudo apt-get install openjdk-11-jre openjfx
java --version

Finally lets install the SAP Gui:

cd JavaGUI/
java -jar PlatinGUI750_5-80002496.JAR install

The important step during the installation of SAP Gui for Java Rev 5 is to define the option for the module path. The module path hast to point to the OpenJFX lib-path:


Now you should be able to run the SAP Gui on Linux Mint 20

Eclipse ADT

When using Eclipse with ADT in combination with SAP Gui for Java and receiving the following error:

"The system reqirements are not met.Could not find: javafx.propertiesin: /usr/lib/jvm/java-11-openjdk-amd64/libYour Java Virtual Machine seems not to support JavaFX, required to run the SAPGUI for Java 7.50 rev 5.Please make sure you provide a valid path to the Java FX modules during guiinstallation."

You also have to add the OpenJFX path to the eclipse.ini file. Read more about it here.


[Software] Save battery power on laptops

With TLP I was able to extend the battery life of my ThinkPad E595 significantly.

“TLP is a feature-rich command line utility for Linux, saving laptop battery power without the need to delve deeper into technical details.”

If you prefer tools with UI, check TLPUI: https://github.com/d4nj1/TLPUI
There is also a repository for it:

sudo add-apt-repository ppa:linuxuprising/apps
sudo apt update
sudo apt install tlpui

When using a ThinkPad, there are specific kernel modules that can be installed.

Check with tlp-stat -b

Install with:

sudo apt install acpi-call-dkms tp-smapi-dkms

Another tool to monitor your power usage is PowerTOP:

“PowerTOP is a Linux tool to diagnose issues with power consumption and power management.”

[Shell] User and Group management & File permissions

  • User and Group management
    • id
    • useradd
      • -c – Full name
      • -e – Expiration date
      • -s – Default shell
      • -d – Home directory
    • passwd
    • usermod
      • -l – rename
      • -L – Lock
      • -U – unlock
    • userdel
      • -r – remove user data
    • groupadd
    • groupmod
    • gpasswd [-a -d -A] [user1, user2] [group]
    • newgrp [group]
  • su vs. su – vs. sudo
    • visudo
  • File permissions
    • UGO – User, Group, Other
    • RWX – Read, Write, Execute
    • chmod -R g+x (grant recursive execute permission to group)
      • r = 4
      • w = 2
      • x = 1
      • = 0
      • rwxrwxrwx = 777
      • rw-rw-rw- = 666
      • rwxrwxr–- = 774
      • rw-rw—- = 660
      • rw-r—–- = 640
    • chown
    • chgrp
    • umask


[Router/Firewall] Hard- & Software Sammlung



Einfach zu bedienende Fertiglösungen

[NAS] OpenSource NAS-Systeme & Self-hosting Lösungen


TrueNAS Core (FreeBSD) / TrueNAS Scale (Debian)
XigmaNAS (FreeBSD/FreeNAS, ehemals NAS4FREE)
OpenMediaVault (Debian)
Xpenology (bootloader for Synology’s DSM)
OmniOS Community Edition (Illumos) mit Napp-IT
Rockstor (CentOS)

Self-hosting / Hypervisor

YunoHost (Debian)
Proxmox (Debian)
OmniOS Community Edition (Illumos)
SmartOS (Illumos)
Danube Cloud (SmartOS)
XCP-ng (XenServer / heute Citrix Hypervisor)

[Shell] SSH Passwordless Login Using SSH Keygen

Generate key, copy key to server and finally ssh passwordless into your server.

ssh-kegen -t rsa
ssh-copy-id root@ip
ssh root@ip

View your generated key with:

cat /home/user/.ssh/id_rsa           //local
cat /home/user/.ssh/authorized_keys  //server

To disable password authentication permanently you have to edit the ssh config. Be sure to first backup before editing. Now just set PasswordAuthentication to “no” in your config and restart the ssh daemon.

cp /etc/ssh/sshd_config /etc/ssh/sshd_config_bak
nano /etc/ssh/sshd_config
service ssh restart

[Mint] Installing Manjaro KDE Plasma in VirtualBox 6.0 on Linux Mint 19.2 Cinnamon

Install VirtualBox 6.0 on Linux Mint.

wget -q https://www.virtualbox.org/download/oracle_vbox_2016.asc -O- | sudo apt-key add -
echo "deb [arch=amd64] https://download.virtualbox.org/virtualbox/debian bionic contrib" | sudo tee /etc/apt/sources.list.d/virtualbox.list
sudo apt-get update
sudo apt-get install -y virtualbox-6.0

Download the Manjaro ISO here.
Run VirtualBox and create a new VM with type “Linux” and version “Arch Linux (64-bit)”. If done, go to Settings -> Display and switch Graphics Controller to “VBoxVGA” to be able to change the screen resolution of your VM. For transparency effects, you can also check “Enable 3D Acceleration”.
(Changing this setting didn’t work on my existing VM, only when creating a new VM. So it’s important to do this step before installing the OS.)

Now go to Storage and add your Manjaro ISO as optical drive.

Start the VM and go through the Manjaro installation process. If done, shutdown your VM, go back to settings and remove the Manjaro ISO as optical drive. Else it will boot again into the installer. Now start the VM again.

To run with the VirtualBox Guest Additions, you only have to install virtual-box-utils inside your VM:

sudo pacman -S virtualbox-guest-utils