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How to Install CentOS 9 Step-by-Step

Here is a clear, step-by-step guide on how to install CentOS Stream 9 (the current “CentOS 9” in 2026) on a physical machine or virtual machine. The process uses the Anaconda graphical installer, which remains largely unchanged since the initial release.

Note: In 2026, always use the latest CentOS Stream 9 ISO from official mirrors, as the distribution receives continuous updates. The DVD ISO is recommended for most users because it includes many packages for offline installation.

Step 1: Download the CentOS Stream 9 ISO

  1. Go to the official CentOS download page: https://www.centos.org/download or directly to a mirror index: https://mirror.stream.centos.org/9-stream/BaseOS/x86_64/iso/
  2. Download the latest DVD ISO file:
    • Look for CentOS-Stream-9-latest-x86_64-dvd1.iso (around 14 GB)
    • Or a dated version like CentOS-Stream-9-20260223.0-x86_64-dvd1.iso
  3. (Recommended) Verify the download integrity using the provided .MD5SUM or .SHA256SUM file from the same directory.

For virtual machines (VMware, VirtualBox, KVM, etc.), you can mount this ISO directly.

Step 2: Create Bootable Media

  • Physical machine: Use a tool like Rufus (Windows), balenaEtcher, Fedora Media Writer, or dd (Linux/macOS) to write the ISO to a USB drive (≥8 GB).
  • Virtual machine: Attach/mount the ISO file as a virtual CD/DVD drive and set it to boot first.

Step 3: Boot from the ISO

Restart your computer (or power on the VM) and boot from the USB/ISO.

You will see the boot menu:

  • Select Install CentOS Stream 9 (usually the first option) and press Enter.

The installer loads and performs a media check (it may take a minute).

Step 4: Welcome & Language Selection

The graphical Anaconda installer starts.

  • Choose your preferred language for the installation process (e.g., English).
  • Click Continue.

Step 5: Installation Summary Screen

This is the main configuration hub. All items marked with a warning (!) must be addressed before proceeding.

Typical sections to configure:

  1. Keyboard
    • Add or select your layout (e.g., US English).
  2. Time & Date
    • Select your region and city (e.g., Asia → Hong Kong).
    • Enable Network Time (NTP) for automatic synchronization.
  3. Installation Destination
    • Select the disk where you want to install CentOS.
    • Choose Automatic partitioning for beginners (it creates standard /boot, swap, and / partitions).
    • Or choose Custom for advanced layouts (e.g., separate /home, LVM).
    • Click Done → Accept Changes.
  4. Network & Hostname
    • Enable network interfaces (Ethernet or Wi-Fi).
    • Set a hostname (e.g., myserver.local).
    • Configure IPv4/IPv6 if needed (DHCP is default).
  5. Software Selection
    • Choose a base environment:
      • Minimal Install (most common for servers — no GUI)
      • Server with GUI (includes GNOME desktop)
      • Workstation (full desktop experience)
    • Add-ons: Select additional packages like “Development Tools”, “System Tools”, etc., if desired.
  6. Root Password (and User Creation)
    • Set a strong root password.
    • (Optional but recommended) Create a non-root user with administrator privileges.

Once all required sections are green (no warnings), click Begin Installation.

Step 6: Installation Progress

The installer formats disks, downloads/installs packages, and configures the system.

  • This can take 5–30 minutes depending on hardware and ISO type (DVD vs. boot+network).

Step 7: Complete & Reboot

When finished, you will see:

  • Click Reboot System.

Remove the USB/ISO media (or disconnect in VM) so it boots from the hard drive.

Step 8: First Boot & Login

  • If you chose a GUI: Log in with your user or root.
  • If minimal/server install: You get a text console login.

Run these first commands after login:

Bash
sudo dnf update -y
sudo reboot

This applies the latest security patches and bug fixes (CentOS Stream 9 is continuously updated).

Common Post-Install Tips

  • Enable extra repositories (very useful):
    Bash
    sudo dnf install epel-release -y
sudo dnf upgrade -y
  • If you need a desktop later (on minimal install):
    Bash
    sudo dnf groupinstall "Server with GUI" -y
sudo systemctl set-default graphical.target
sudo reboot
  • Check your version:
    Bash
    cat /etc/centos-release
uname -r

That’s it! You now have a fresh CentOS Stream 9 system ready for server, development, or learning use.

If you’re installing in a VM and want visual references, many online guides (like those from Tecmint or ComputingForGeeks from 2022) still show nearly identical screens, as Anaconda hasn’t changed dramatically. The main differences in 2026 are updated package versions and kernel (usually 5.14 series with backports). Enjoy your new system! 🚀

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