The guide explains how to transform a headless CentOS 9 Stream into a complete KDE Plasma desktop by first updating the base system and enabling the CRB repository, then installing either the full “KDE Plasma Workspaces” group or its core components such as plasma‑desktop and sddm. After pulling in these packages, it walks you through disabling GDM, enabling SDDM, and rebooting so that the login screen offers a KDE session to choose from. Once logged in, you can apply quick tweaks like turning off automatic updates, adding the EPEL repository for extra applications, or installing missing components such as PulseAudio if sound is absent. The end result is a lightweight yet fully featured KDE workstation that replaces the default GNOME stack on a solid CentOS base.

How to Install KDE Plasma Desktop on CentOS 9 Stream

The goal? Turn a headless CentOS 9 Stream into a slick, multitasking desktop powered by KDE Plasma without pulling in an entire GNOME bundle that you’ll never touch.

Update the Base System

sudo dnf upgrade -y

CentOS 9 Stream is a rolling‑release; keeping packages fresh avoids version clashes later when you pull in KDE components.

Enable the “DLC” (formerly PowerTools) Repository

KDE pulls in development libraries that live there, so you need to unlock it:

sudo dnf config-manager --set-enabled crb # core repos are already enabled by default

If you’re on a minimal install, that’s all you need; the “DLC” repo is automatically part of the CRB stream.
Notice: Trying to install Plasma before enabling this will leave you with broken dependencies.

Install the KDE Package Group

sudo dnf groupinstall "KDE Plasma Workspaces"

This pulls in:

• plasma-desktop – the shell itself
• sddm – the display manager that ships with Plasma
• kde-applications – a curated set of utilities (file manager, terminal, etc.)

If you prefer to keep your install leaner, replace the group with individual packages:

sudo dnf install plasma-desktop sddm xorg-x11-server-Xorg

Switch to SDDM (Optional but Recommended)

CentOS ships GDM by default, which will still be there after installing KDE. To make Plasma the default login experience:

sudo systemctl disable gdm.service
sudo systemctl enable sddm.service

Then reboot.
If you prefer to keep both, just pick your session at the SDDM screen.

Reboot and Choose KDE

sudo reboot

When the machine comes back up:

1. At the login prompt select “KDE Plasma” from the session menu.
2. Log in normally.

You’re now running a full‑featured desktop that feels like a modern laptop but sits on a robust CentOS base.

6. Quick Tweaks for Comfort

• Turn off automatic updates if you want to control when new KDE releases hit your system:

  sudo dnf config-manager --set-disabled updates
  

• Add the “Extra Packages for Enterprise Linux” (EPEL) repo for goodies like vlc or gimp that KDE users love:

  sudo dnf install epel-release
  

• Install a more powerful terminal such as Konsole (already included) or the new kitty if you want better GPU acceleration.

7. Common Pitfalls

Symptom	Likely Cause	Fix
Login screen is black	Missing X.Org server	Install xorg-x11-server-Xorg
“No matching packages” error on groupinstall	DLC repo disabled	Enable CRB/DLC as in step 2
KDE starts but no sound	PulseAudio not installed	sudo dnf install pulseaudio

That’s it. You’ve upgraded a bare‑bones CentOS 9 Stream into a full KDE Plasma workstation. Now feel free to tweak themes, add widgets, or just enjoy that satisfying “I can do everything from the GUI now” feeling.