Finding Red Hat Boot Images

Red Hat boot floppies used to be divided into local media boot floppy images called boot.img and network-capable boot images called bootnet.img. These can still be seen in the older (nonenterprise) sections of Red Hat mirror sites such as the one we maintain at Rackspace:

• ftp://mirror.rackspace.com/redhat/linux/7.3/en/os/i386/images/

This system was nice, but with all the motherboard chip sets, IDE controllers, and network card drivers, Red Hat quickly ran out of room on that bootnet.img floppy image.

To remedy this, Red Hat now provides only one boot floppy image, called bootdisk.img. It allows for basic local HD- and CD-based installs to IDE drives. For network installs or installs that require network drivers (FTP, HTTP, NFS installs), SCSI/RAID or PCMICA mass storage drivers (that is, any third party drivers), bootdisk.img needs to load the drivers (after booting from bootdisk.img) from either the drvnet.img, drvblock.img, or pcmciadd.img driver disk, respectively. This process can be a nuisance, so Red Hat also has a bootable CD image that has all of these drivers built in. Figure 4-2 shows the boot screen from the bootdisk.img or the boot.iso (CD).

These boot media images are available on all Fedora Core FTP mirror sites as well as on Fedora Core CD 1. See Table 4-1 for a description of what each image does.

Table 4-1: Fedora Core Boot Images on CD and Mirror Sites

Media Files	Description
Bootdisk.img	Required boot floppy image for Fedora Core installs from CD or hard drive media. Also base boot for network and block device (SCSI/RAID) installs (1.44M).
Drvblock.img	Supplemental block device drivers such as storage controllers, SCSI, and RAID controllers (1.44M).
Drvnet.img	Supplemental network device drivers such as NIC (network interface card) drivers (1.44M).
Pcmciadd.img	Supplemental PCMCIA/PC-Card driver disk (1.44M)
Pxeboot/	The directory of files to put on your PXE/DHCP server to allow pure network-based boot and installs (~3-4M)
Boot.iso	A standalone CD image that includes all the boot and driver info from bootdisk.img, the drvblock.img, drvnet.img, and the pcmpciadd.img floppy images. Good for doing machine boots for single media network installs.

To get a listing of Fedora Core mirror sites where you can download these boot images, go to http://fedora.redhat.com/download/mirrors.html.

Considering Network Install Options

There are three general boot options for performing a network install: floppy disks, CDs, and PXE.

• Stock or custom boot floppy network installs: This type of installation uses the bootdisk.img floppy image, along with one to three standard driver disks. These driver disks enable the install time environment to get to network or media that has other install-related files (such as kickstart config files). Within such floppy-based installations you have two alternatives:

  • Stock: Use the stock bootdisk.img boot floppy image and whichever of the three driver disks you might require (block device driver, network driver, and PCMCIA driver disk images). This method can require manually swapping floppies at least once, so this makes for a poor automated install process. You also have to make your clients manually point the boot/install process to a centralized network share of your kickstart config file(s) where all of your install parameters are defined. This method is very prone to typos and not very user friendly.

  • Slightly Customized: This method uses the same one to four driver floppies as with the Stock method, but you slightly modify the boot disk to have your boot config file automatically point to the correct network location for the kickstart config file(s). Of the two main forms of floppy installs, this tends to be the more popular since it is more automated.

    Note

    There is a third, less common method that can totally automate the entire install process all from a single boot floppy (with network and other drivers built-in), but it is technically very complex and beyond the scope of this chapter. This is a method by which you can make your own custom, automated, single, hybrid boot/driver floppy with all the drivers that you need. This single boot/install/driver floppy has your own custom initrd (initial RAM disk) file needed to automate everything from a single boot disk. If you don't know what an initrd file is, then you probably don't want to even think about this option. If you're still interested more information on this useful subject can be found at http://linuxcourse.rutgers.edu/bootdisk.html.

    The fact is we are more and more moving away from floppies as a common media, especially for specialized boot environments like kickstart. Some newer laptops no longer come with floppy drives. Keep in mind, however, that if you prefer using floppies, the first of these alternatives is simpler for you (creating the floppies), but more difficult and error prone for the end user doing the install. The second method is probably the way most people should do floppy-based network installs, as it is much easier for the end user, still requires a bit of floppy swapping by the user, but only slight customization on your behalf. Details on the second option are covered in the Creating Customized Boot Floppies section later in the chapter.

  Note

  It should also be noted that while it is considered a technically bad management practice (in an enterprise at least) to put your ks.cfg file(s) on the floppy itself, this is still an option available to you. If you decide to do this, the boot option to point anaconda to the floppy for the ks.cfg file from the boot: prompt is linux ks=floppy.

• Stock or Custom Boot CD: Use the boot.iso CD image, and either have your clients manually point to a centralized HTTP share of your ks.cfg files or make your own slightly customized CD image that totally automates this. Either way, you have a single media network install solution. These procedures are covered in the Making a Network Install Boot CD section.

• LAN PXE boot solution: This solution is available only if all of your people have a PXE-capable network card and have the card and machines BIOS set up for PXE network booting. Since most IT administrators do not have access (or clearance) to set up a full PXE boot environment, and since this configuration would also have to be duplicated across all company LANs (since PXE/DHCP/bootp is a LAN broadcast only solution), this solution falls outside the scope of this book. If interested in this option, see www.redhat.com/docs/manuals/enterprise/RHEL-3-Manual/sysadmin-guide/ch-pxe.html.

Given all this, the boot CD seems to be the easiest and more forward-compatible network install option for doing Red Hat Enterprise or Fedora Core kickstart/anaconda installs. Since all CDs and machines are pretty much bootable nowadays, it's usually easier to either use a stock boot.iso boot CD and point it manually to your network-based ks.cfg file(s) or to modify the boot.iso image for automatic kickstarts for fire-and-forget installs. Rebuilding the floppy image with a single disk hybrid OS/kernel/initrd setup is beyond the scope of this chapter, but we give a link to more information on doing this in one of the aforementioned notes. Let's start with the older and more unruly to manage multifloppies method, and then we'll turn to the more elegant modern CDs method.

Creating Customized Boot Floppies

If you want to do your network-based OS install using the three floppy images, first copy the bootdisk.img, drvnet.img, and drvblock.img, from the CD 1 (in Fedora/images/) or from a mirror site. Then follow these steps:

1. Write your floppy images out to three blank/formatted disks using dd:

   # dd if=bootdisk.img of=/dev/fd0
   
   # dd if=drvnet.img of=/dev/fd0
   
   # dd if=drvblock.img of=/dev/fd0
   
   

   Note

   The drvblock floppy is needed only if you're installing to or from mass media storage such as SCSI, RAID, or specialized storage hardware. It's not bad to have, but usually not required on most PCs.

2. Insert and mount the bootdisk floppy:

   #  mount /dev/fd0 /mnt/floppy/
   #  cd /mnt/floppy/
   #  ls
   boot.msg       initrd.img    options.msg   rescue.msg   splash.lss   vmlinuz
   general.msg    ldlinux.sys   param.msg     snake.msg    syslinux.cfg
   

   Now with your new boot floppy mounted, you can start editing and customizing it to point to your kickstart files out on the network.

   Tip

   If you don't want to have to do this every time you want another identical boot disk, then after you work all the bugs out and tweak out your bootdisk just so, you can loopback mount the actual img file as a loopback file system (with the -o loop mount option): # mount -o loop,wr bootdisk.img /mnt/floppy/ cd into /mnt/floppy and edit away on your "phantom floppy" image. Then when you're done: # cd # umount /mnt/floppy and from then on when you dd a copy of the img file to a disk you will have all of your changes! Try doing that on a stock Windows box!

3. After mounting your new bootdisk floppy, you need to make some space on the disk by deleting the .msg files:

   # /bin/rm *.msg
   
   

   Tip

   Keep a few of these .msg files around. These would be handy later when you decide that you want an interactive user menu with directions and help options.

4. Now edit the syslinux.cfg file to look like this and add the bold bit (all on one line):

   default linux
   prompt 1
   timeout 1
   label linux
     kernel vmlinuz
     append initrd=initrd.img ramdisk_size=8192
             ks=http://example.com/installs/ks-server.cfg
             ksdevice=eth0 dd <--- Note
   
   label memtest86
     kernel memtest
     append -
   
   

   Note

   The trailing dd boot option in the isolinux.cfg file has nothing to do with the dd command that we used earlier. The dd boot option is what tells anaconda to ask for the drvnet and/or drvblock driver disks so that it can either get online or install SCSI or RAID card drivers-must in our case since we need the dvrnet disk's network card drivers to get online and our kickstart file! This required "floppy swapping" illustrates how floppy's time has come and gone, and we will see how using the single boot CD boot.iso is a much nicer and more modern option.

5. After you're done with your edits, cd back home and unmount the floppy:

   # cd
   # umount /mnt/floppy
   

Tip

You can keep the boot.msg if you want to have user messages and a time out with pointers to the various ks.cfg files that you have on your web server. It's up to you, but just watch the space on the floppy. You may have to do your editing off disk and then copy your final edits back over. Also, if you use an editor like vi or vim (which most of you will), and you want to quickly do your edits in place (on the floppy), then invoke vi/vim like this: vi -n/mnt/floppy/syslinux.cfg. The -n will keep a temporary swap file from being created by vim (which can create really problems when trying to edit files when you have very little elbow room). Finally, unlike most UNIX/Linux systems, these config files are standard (or nonstandard) MS-DOS CR/LF text files, so you can actually get away with using DOS/Windows type editors on them, such as notepad. The filesystem is also FAT(12) so it can be accessed from just about any OS without much of a problem.

Now take your new bootdisk and driver disks to a test machine and see how they work!

Making a Network Install Boot CD

Given the problems with floppy-based network kickstart installs, let's look at the CD option via the stock CD boot image boot.iso from our own CD 1's path Fedora/images/boot.iso.

Note

You can get this CD boot image boot.iso from one of the Fedora Core mirror sites if you don't have the Fedora stock install CDs handy.

We're going to cover a couple of different ways of installing from a CD-an easy (stock) way and a not-so-easy (custom) way. The easy way is, well, easier for the admin upfront, but it forces the clients (or installer person) to type in special pointers to point to your centralized ks.cfg file(s) out on the network. The second, not-so-easy, way is cool because it requires no intervention from the install person at all (other than inserting a CD), but it takes a lot more footwork on your part.

More Floppy and CD Customization Information

For more information on customizing your floppy and CD images, look at the following links:

• http://linuxcourse.rutgers.edu/bootdisk.html

• www.linuxjournal.com/article.php?sid=6473

• http://birger.sh/computing/RedHat_9_customized_install_media_howto.html

• http://acd.ucar.edu/~fredrick/linux/linux-kickstart/