Chapter 2. Performing the pre-customization tasks

download PDF

2.1. Working with ISO images

In this section, you will learn how to:

  • Extract a Red Hat ISO.
  • Create a new boot image containing your customizations.

2.2. Downloading RH boot images

Before you begin to customize the installer, download the Red Hat-provided boot images. You can obtain Red Hat Enterprise Linux 9 boot media from the Red Hat Customer Portal after login to your account.

  • Your account must have sufficient entitlements to download Red Hat Enterprise Linux  9 images.
  • You must download either the Binary DVD or Boot ISO image and can use any of the image variants (Server or ComputeNode).
  • You cannot customize the installer using the other available downloads, such as the KVM Guest Image or Supplementary DVD; other available downloads, such as the KVM Guest Image or Supplementary DVD.

For more information about the Binary DVD and Boot ISO downloads, see Red Hat Enterprise Linux 9 Performing an advanced RHEL 9 installation.

2.3. Extracting Red Hat Enterprise Linux boot images

Perform the following procedure to extract the contents of a boot image.


  1. Ensure that the directory /mnt/iso exists and nothing is currently mounted there.
  2. Mount the downloaded image.

    # mount -t iso9660 -o loop path/to/image.iso /mnt/iso

    Where path/to/image.iso is the path to the downloaded boot image.

  3. Create a working directory where you want to place the contents of the ISO image.

    $ mkdir /tmp/ISO
  4. Copy all contents of the mounted image to your new working directory. Make sure to use the -p option to preserve file and directory permissions and ownership.

    # cp -pRf /mnt/iso /tmp/ISO
  5. Unmount the image.

    # umount /mnt/iso

Additional resources

Red Hat logoGithubRedditYoutubeTwitter


Try, buy, & sell


About Red Hat Documentation

We help Red Hat users innovate and achieve their goals with our products and services with content they can trust.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. For more details, see the Red Hat Blog.

About Red Hat

We deliver hardened solutions that make it easier for enterprises to work across platforms and environments, from the core datacenter to the network edge.

© 2024 Red Hat, Inc.