RedHat ES / CentOS / Oracle Linux - install from USB

1. You need an 4GB USB Stick ... even better would be 8GB.
   You also need the original install media.
   
2. Prepare your  USB Stick
1. Method A
   The easy way might be to use Grub4DOS - but older server might no be able to boot from the stick.
   
2. Method B
   So the safe method is to download RipLinux ISO image and mkusb.sh from the RipLinux Homepage (http://www.tux.org/pub/people/kent-robotti/looplinux/rip/) and to format the USB Stick with mkusb.sh according to the RipLinux documentation.
   
3. Mount the USB stick and create a directory in the root directory to hold your Linux install files. I'll call mine /rhes65.
   
4. Copy the installation files to the stick
   
   Mount the ISO image - and copy the content of the ISO to the stick.  I use tar for this purpose. Assuming your image is mounted to /media/cdrom and your stick is monted to /media/usb ...
   
   # tar -C /media/cdrom -c . | tar -C /media/usb -x -v
   
5. Create an entry for grub (menu.lst) and syslinux (syslinux.cfg).  Edit those two files located on the USB in /boot/syslinux an add following lines:
   
   ### for syslinux.cfg ###
   LABEL Install RedHat ES 6.5! (64-bit kernel)
   KERNEL /rhel65/isolinux/vmlinuz
   APPEND initrd=/rhel65/isolinux/initrd.img ks=hd:sda1:/es65.cfg method=hd:sda1:/rhel65/
   
   ### for menu.lst ###
   title Install RedHat ES 6.5! (64-bit kernel)
   kernel /rhel65/isolinux/vmlinuz ks=hd:sda1:/es65.cfg method=hd:sda1:/rhel65/
   initrd /rhel65/isolinux/initrd.img
   
6. Those entries assume, that you do want to supply an kickstart-file named es65.cfg located in / on the USB stick.  If you do not habe an kickstart file, simply remove the "ks=" option from the files above.
   
7. Boot from the stick ... and have fun