The kickstart installation needs to access an installation tree. An installation tree is a copy of the binary Red Hat Enterprise Linux CD-ROMs with the same directory structure.
If you are performing a CD-based installation, insert the Red Hat Enterprise Linux CD-ROM #1 into the computer before starting the kickstart installation.
If you are performing a hard-drive installation, make sure the ISO images of the binary Red Hat Enterprise Linux CD-ROMs are on a hard drive in the computer.
If you are performing a network-based (NFS, FTP, or HTTP) installation, you must make the installation tree available over the network. Refer to the Preparing for a Network Installation section of the Red Hat Enterprise Linux Installation Guide for details.