Make USB pen drive as a bootable device (RedHat)

If you cannot boot from the DVD/CD-ROM drive, but you can boot using a USB device, such as a USB pen drive, the following alternative boot method is available:

To boot using a USB pen drive, use the dd command to copy the diskboot.img image file from the /images/ directory on the DVD or CD-ROM. For example:

dd if=diskboot.img of=/dev/sda

Your BIOS must support booting from a USB device in order for this boot method to work.