For system, network and cloud administrators

How to install and use tmux

How to : Arch Linux terminal, macOS terminal, OpenSUSE terminal, RHEL terminal, tmux, Ubuntu terminal
Published by Iulian Donici on 19.07.2020 and updated on 14.12.2022 at 19:14

tmux is a very useful tool when working with the terminal. It basically allows you to start multiple sessions and each one of these sessions can have multiple panes inside it. tmux is a terminal tool focused on window and session management. tmux is available for: Debian/Ubuntu, Fedora, RHEL/CentOS, Arch Linux, OpenSUSE, macOS.

How to change the MTU of a network interface with ifconfig in Linux

How to : ifconfig, MTU, netstat, Ubuntu, Ubuntu server, Ubuntu terminal
Published by Iulian Donici on 27.02.2020 and updated on 07.03.2021 at 19:35

Your network interface might not act properly by not having an speed unknown value for example and this is sometimes caused by an abnormal MTU value for your network interface. You can change that using the ifconfig command.

How to bring a network interface up or down with ifconfig in Linux

How to : ifconfig, ip a, ip link show, Ubuntu, Ubuntu desktop, Ubuntu server, Ubuntu terminal
Published by Iulian Donici on 26.02.2020 and updated on 26.02.2021 at 18:40

On some machines running Ubuntu frequently, you can easily restart (down/up state) a network interface by ultimately using the ifconfig command.

How to uninstall Apache2 on Linux

How to : Apache2, terminal, Ubuntu, Ubuntu server, Ubuntu terminal, web server
Published by Iulian Donici on 22.01.2020 and updated on 26.02.2021 at 16:48

Ubuntu server 18.04 LTS

Check the Apache2 process status

sudo /etc/init.d/apache2 status

If you’re seeing an “Active (running)“ message then it means that your Apache2 process is still running and we need to stop it.

How to uninstall Apache2 on Linux – checking the Apache2 **status** on Ubuntu 18.04.3 LTS

Stop the Apache2 process

sudo /etc/init.d/apache2 stop

How to uninstall Apache2 on Linux – **stopping** the Apache2 service on Ubuntu 18.04.3 LTS

Check the Apache2 process status, again.

sudo /etc/init.d/apache2 status

How to uninstall Apache2 on Linux – checking **status** after **stopping** the Apache2 process on Ubuntu 18.04.3 LTS

Notice that now, the “Active” section says “inactive“.

Uninstall Apache2 by purging.

sudo apt-get purge apache2* -y

How to uninstall Apache2 on Linux – **purging** Apache2 on Ubuntu 18.04.3 LTS

Verify if anything related to the Apache2 service has been removed

 sudo apt-get autoremove -y

How to uninstall Apache2 on Linux – **autoremove** any leftovers after **purging** on Ubuntu 18.04.3 LTS

Verify if any file or folders have been left on the server.

whereis apache2

How to uninstall Apache2 on Linux – **whereis** Apache2 on Ubuntu 18.04.3 LTS

If the result/output of the command above is empty, then Apache2 has been successfully uninstalled from your Ubuntu 18.04 LTS.

How to install an run OpenVPN?

How to : OpenVPN, Ubuntu desktop, Ubuntu server, Ubuntu terminal, VPN
Published by Iulian Donici on 21.01.2020 and updated on 26.02.2021 at 16:32

OpenVPN is a software compatible with both Windows and Linux, often used in corporations for creating secure connections towards their own internal IT infrastructure.

Install OpenVPN on Ubuntu 18.04/20.04 LTS

Open your Ubuntu terminal and type:

sudo apt-get install openvpn openvpn-systemd-resolved

Run OpenVPN on Ubuntu 18.04/20.04 LTS

Open your Ubuntu terminal and type:

sudo openvpn --config path-to-openvpn-config-file.ovpn

After running OpenVPN, the system will require you to enter your local super user (if prompted) and after that, for your OpenVPN user and password.