KVM virt-manager: Install CentOS As Guest Operating System

Here are the steps to install CentOS as a guest operating system in KVM using virt-manager:

1. Launch virt-manager by running the command virt-manager in a terminal window or by launching it from the Applications menu.
2. Click the Create a new virtual machine button or select File > New Virtual Machine.
3. In the New VM wizard, select Local install media (ISO image or CDROM).
4. Click the Browse button and navigate to the CentOS ISO image file on your system.
5. Select the ISO file and click Choose Volume.
6. Click Forward to proceed.
7. Choose the appropriate OS type for CentOS (e.g. Linux) and version (e.g. CentOS 8.x).
8. Set the amount of memory you want to allocate to the virtual machine. The recommended minimum is 2048 MB, but you can adjust this to meet your requirements.
9. Select the number of CPUs you want to assign to the virtual machine. The recommended minimum is 1, but you can adjust this to meet your requirements.
10. Choose the amount of storage you want to allocate to the virtual machine’s virtual hard drive.
11. Choose the virtualization method you want to use. The default is KVM, which should be fine for most users.
12. Choose the network settings you want to use. The default is NAT, which allows the virtual machine to communicate with the host system and other virtual machines on the same network.
13. Click Finish to create the virtual machine.
14. Start the virtual machine by selecting it in virt-manager and clicking the Play button.
15. The CentOS installation process should start. Follow the prompts to complete the installation.

Once the installation is complete, you should be able to run CentOS as a guest operating system in KVM.