Chapter 7. Boot Devices

Automated installation (or kickstart) is an essential part of efficient system provisioning. This chapter describes how to prepare different types of boot media for use with kickstarting clients.
For more detailed information on using kickstart for provisioning, see the RHN Satellite Getting Started Guide.
Before beginning, locate the standard Red Hat Enterprise Linux CD boot image boot.iso. You will need to create work directories for different boot images, and populate them with the necessary boot files. Switch to the root user, and enter the following commands: 
mkdir -p temp cd/isolinux pxe/pxelinux.cfg usb/extlinux usb/temp
mount -o loop boot.iso temp
cp -aP temp/isolinux/* cd/isolinux/
cp -aP temp/isolinux/* pxe/
cp -aP temp/isolinux/* usb/extlinux/
umount temp
chmod -R u+rw cd pxe usb

Procedure 7.1. CD Boot Media

Note

The backslash "\" is used below to represent a continuation of one line at the shell prompt.
  1. Change to the ./cd directory: 
    cd ./cd
  2. Copy the /usr/lib/syslinux/menu.c32 file to the CD: 
    cp -p /usr/lib/syslinux/menu.c32 isolinux
  3. Open the isolinux/isolinux.cfg file in your preferred text editor, and add the following line: 
    mkisofs -o ./custom-boot.iso -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot \
  -boot-load-size 4 -boot-info-table -J -l -r -T -v -V "Custom RHEL Boot" .
  4. Customize any boot parameters and targets in isolinux.cfg as needed for CD booting.
  5. Burn the details to the CD to complete the procedure.

Procedure 7.2. PXE Boot

  1. Change to the /pxe directory: 
    cd ./pxe
  2. Copy the /usr/lib/syslinux/menu.c32 file to the /pxe directory: 
    cp -p /usr/lib/syslinux/menu.c32 .
  3. Move the isolinux.cfg file to pxelinux.cfg/default: 
    mv isolinux.cfg pxelinux.cfg/default
  4. Remove the temporary files: 
    rm -f isolinux.bin TRANS.TBL
  5. Copy the /usr/lib/syslinux/pxelinux.0 file to the /pxe directory: 
    cp -p /usr/lib/syslinux/pxelinux.0 .
  6. Open the pxelinux.cfg/default file in your preferred text editor, and customize any boot parameters and targets as needed for PXE booting.

Procedure 7.3. USB Boot Media

Warning

Be extremely careful when carrying out these command as root (required for most critical parts). These commands access device files and using them incorrectly could irrecoverably damage your system. The example below uses /dev/loop0 for mounting, make sure you use the correct device for your system. You can check which is the correct device using the losetup -f command.
  1. Change to the /usb directory: 
    cd ./usb
  2. Copy the /usr/lib/syslinux/menu.c32 file to the extlinux/ directory: 
    cp -p /usr/lib/syslinux/menu.c32 extlinux/
  3. Move the extlinux/isolinux.cfg file to extlinux/extlinux.conf: 
    mv extlinux/isolinux.cfg extlinux/extlinux.conf
  4. Remove the temporary files: 
    rm -f extlinux/isolinux.bin extlinux/TRANS.TBL
  5. Convert the custom-boot.img file and copy it: 
    dd if=/dev/zero of=./custom-boot.img bs=1024 count=30000
  6. Discover the correct mounting location for the loopback device: 
    losetup -f
/dev/loop0
    Set up the loopback device with the boot image: 
    losetup /dev/loop0 ./custom-boot.img
  7. Open the fdisk utility: 
    fdisk /dev/loop0
    Create one primary bootable partition on the device. This can be done by using the following key press combination: n p 1 Enter Enter a 1 p w
  8. Copy the master boot record (MBR) to the loopback device: 
    dd if=/usr/lib/syslinux/mbr.bin of=/dev/loop0
  9. Add partition maps to the loopback device: 
    kpartx -av /dev/loop0
  10. Create the file system: 
    mkfs.ext2 -m 0 -L "Custom RHEL Boot" /dev/mapper/loop0p1
  11. Mount the device: 
    mount /dev/mapper/loop0p1 temp
  12. Delete temporary files: 
    rm -rf temp/lost+found
  13. Copy the extlinux/ directory to a temporary location: 
    cp -a extlinux/* temp/
  14. Install the bootloader in the temporary location: 
    extlinux temp
  15. Unmount the temporary location: 
    umount temp
  16. Delete the partition maps on the loopback device: 
    kpartx -dv /dev/loop0
  17. Delete the loopback device: 
    losetup -d /dev/loop0
    Synchronize the file system changes: 
    sync
  18. Open the extlinux.conf file in your preferred text editor, and customize any boot parameters and targets as needed for USB booting.
  19. Transfer the image to a USB device to complete the procedure. Insert the device, and run the dmesg command to check the mounting location. In this example, it is /dev/sdb.
    Unmount the USB device: 
    umount /dev/sdb
    Copy the image to the USB device: 
    dd if=./custom-boot.img of=/dev/sdb