Installing CentOS or Red Hat Enterprise Linux (RHEL) using a Kickstart file allows you to automate the installation process and customize the installation to fit your specific needs. Here is how you can install CentOS or RHEL using a Kickstart file with KVM:
Download the CentOS or RHEL installation ISO image and copy it to the host machine.
Create a new virtual machine in KVM with the desired configuration. For example, you can use the following command to create a new virtual machine with 2 CPU cores, 4GB of RAM, and a 20GB disk:
virt-install --name=centos7 --memory=4096 --vcpus=2 --disk path=/var/lib/libvirt/images/centos7.img,size=20 --cdrom=/path/to/centos7.iso --network bridge=br0 --graphics vnc --os-type=linux --os-variant=centos7.0 --noautoconsole
Create a Kickstart file with the desired installation options. You can use the ksvalidator tool to validate the Kickstart file.
Start the virtual machine and press the Tab key at the boot menu to edit the kernel command line. Add the following options to the kernel command line:
inst.ks=http://<kickstart-server>/<kickstart-file>
Replace <kickstart-server> with the URL of the server hosting the Kickstart file, and <kickstart-file> with the path to the Kickstart file on the server.
Enter to boot the virtual machine with the modified kernel command line. The installation process will begin, and the virtual machine will be installed and configured according to the options specified in the Kickstart file.