2.3. Making Minimal Boot Media

A piece of minimal boot media is a CD, DVD, or USB flash drive that contains the software to boot the system and launch the installation program, but which does not contain the software that must be transferred to the system to create a Red Hat Enterprise Linux installation.

Use minimal boot media:

to boot the system to install Red Hat Enterprise Linux over a network
to boot the system to install Red Hat Enterprise Linux from a hard drive
to use a kickstart file during installation (refer to Section 32.8.1, “Creating Kickstart Boot Media”
to commence a network or hard-drive installation or to use an anaconda update or a kickstart file with a DVD installation.

You can use minimal boot media to start the installation process on 32-bit x86 systems, AMD64 or Intel 64 systems, and POWER systems. The process by which you create minimal boot media for systems of these various types is identical except in the case of AMD64 and Intel 64 systems with UEFI firmware interfaces — refer to Section 2.3.1, “UEFI-based systems”.

To make minimal boot media for 32-bit x86 systems, BIOS-based AMD64 or Intel 64 systems, and POWER systems:

Download the ISO image file named boot.iso that is available at the same location as the images of the Red Hat Enterprise Linux 6 installation DVD — refer to Chapter 1, Obtaining Red Hat Enterprise Linux.
Burn boot.iso to a blank CD or DVD using the same procedure detailed in Section 2.1, “Making an installation DVD” for the installation disc, or transfer the boot.iso file to a USB device with the dd command as detailed in Section 2.2, “Preparing a USB flash drive as an installation source”. As the boot.iso file is only around 200 MB in size, you do not need an especially large USB flash drive.

2.3.1. UEFI-based systems

Red Hat does not provide an image to produce minimal boot CDs or DVDs for UEFI-based systems. Use a USB flash drive (as described in this section) to boot the Red Hat Enterprise Linux 6 installer, or use the installation DVD with the linux askmethod option to boot the installer from DVD and continue installation from a different installation source — refer to Section 3.5, “Selecting an Installation Method”.

Use the efidisk.img file in the images/ directory on the Red Hat Enterprise Linux 6 installation DVD to produce a bootable USB flash drive for UEFI-based systems.

Download an ISO image file of the Red Hat Enterprise Linux 6 installation DVD as described in Chapter 1, Obtaining Red Hat Enterprise Linux.
Become root:
```
su -
```
Create a mount point for the ISO image file:
```
mkdir /mnt/dvdiso
```
Mount the image file:
```
mount DVD.iso /mnt/dvdiso -o loop
```
Where DVD.iso is the name of the ISO image file, for example RHEL6-Server-x86_64-DVD.iso.

Transfer efidisk.img from the ISO image file to your USB flash drive:

dd if=/mnt/dvdiso/images/efidisk.img of=/dev/device_name

For example:

dd if=/mnt/dvdiso/images/efidisk.img of=/dev/sdc

Unmount the ISO image file:
```
umount /mnt/dvdiso
```