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To study for the RHCE or RHCT exam, you need to practice with a copy of a Red Hat Linux distribution. Ideally, you should work with a copy of Red Hat Enterprise Linux 3. Unfortunately, it is expensive. But assuming you have a high-speed connection, there are options.
RHEL 3 is based on Red Hat Linux 9. If you install and update this operating system, you can use Red Hat Linux 9 to study for the exams. Just be sure that you have the appropriate version of any software that you're studying. Alternatively, you could even use the version of Fedora Linux (Yarrow) released in November 2003. It's a mixed bag; that Fedora Linux release includes some updates that are in RHEL 3, and others that go beyond RHEL 3.
If you don't have a high-speed connection, downloading the gigabytes of files associated with the latest versions of RHEL can take several days. If Red Hat Linux 9 or Fedora Linux is all that you can or want to afford, and you can accept the differences with Red Hat Enterprise Linux 3, you can purchase downloaded CDs from a source such as CheapBytes (www.cheapbytes.com) or buy a book with the publisher's edition of Red Hat Linux 9. Alternatively, there are third parties who have built RHEL 3 from the publically available source RPMs. I describe these options in more detail in the Introduction to this book.
Generally, these downloaded CDs are available in ISO format, which you can process and write to CDs using the methods I describe in this section.
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To show you that you can use Red Hat Linux 9 or a third-party RHEL 3 rebuild to study for the RHCE and RHCT exams, I've illustrated the detailed installation process in screenshots in Appendix B on the CD-ROM.
As described in the introduction to this book, you can buy a copy of RHEL. Assuming you have a PC with an Intel-style 32-bit CPU, you can purchase the most inexpensive version of this server, Red Hat Enterprise Linux ES. As of this writing, you can purchase the Basic Edition with a one-year subscription to the Red Hat Network for $349. At this price, RHEL ES 3 is available only by download in ISO format; for all practical purposes, this requires a high-speed connection.
While there are versions of RHEL available with packaged CDs, they are significantly more expensive. Once again, let me repeat my belief that you can use Red Hat Linux 9 or the RHEL rebuilds to study for the RHCE and RHCT exams based on RHEL 3.
Red Hat provides free access to the source RPMs for Red Hat Enterprise Linux 3 (RHEL). You can download these source RPMs from ftp.redhat.com (or an FTP mirror site) for free. You can then build your own copy of RHEL using the instructions as described in the Red Hat Enterprise Linux Rebuild mini-HOWTO, available online from www2.uibk.ac.at/zid/software/unix/linux/rhel-rebuild.htm. My understanding is that once you've downloaded and prepared the source RPMs, it takes a couple of days for an average PC to process the source code into binary RPM packages which you can then install on your computer.
While I am not a lawyer, I understand that this is legal because the source code for almost all of the software included with RHEL 3 has been released through the Linux General Public License (GPL).
As I've described in the introduction to this book, there are third-party versions of RHEL 3 available. They are built from the source code RPMs that Red Hat has made freely available, under the Linux General Public License (GPL). While I am not a lawyer, my understanding is that these third parties have complied with the following guidelines:
Software in RHEL 3 that is not licensed under the GPL must not be included. As I understand it, this includes some packages supplied by IBM and not covered on the Red Hat exam.
All software in the third-party version of RHEL 3 must be built from the source code (despite what you might see on eBay, my understanding is that you can't just resell copies of the RHEL binary RPMs, especially the installation CDs).
References to 'Red Hat' must be removed from the software.
Binary updates, such as through up2date or the Red Hat Network, are not allowed. However, this does not exclude updates from revised GPL source code.
As I've described in the introduction, there are three major groups working on a rebuild of RHEL 3. As of this writing, each of these groups have made their work available in ISO format through their Web sites (and mirrors), which you can write to CDs using the techniques I describe shortly.
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The work of these third parties are known as 'rebuilds' because their versions of RHEL 3 are built from source RPMs. They are not 'clones,' as they use the same basic source code used and released by Red Hat.
RHEL 3 is based on Red Hat Linux 9. It includes some improvements that are included in the first release of Fedora Linux in late 2003. Therefore, you could prepare for the RHCE or RHCT exams using one or both of these operating system distributions.
However, these operating systems are not identical. For example, while Red Hat Linux 9 uses the samba-2.2.7 RPM package for sharing with Microsoft Windows computers, RHEL 3 uses the samba-3.0.0 RPM package. With the current Red Hat development model, Red Hat will use Fedora to test some future changes to RHEL. Today, the differences between RHEL 3, Red Hat Linux 9, and the Fedora Linux released in late 2003 are fairly small. However, I believe that the differences between RHEL 4 and Fedora (or its successor) will be more substantial. I'm guessing RHEL 4 will be released in 2005.
If you don't have a copy of Red Hat Enterprise Linux 3, I recommend that you study with one of the third-party rebuilds of RHEL 3.
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If you're using Red Hat Linux 9 or Fedora Linux to simulate the conditions of RHEL 3, you may want to download and install some of the RHEL 3 source RPMS. If you want to install the version of Samba associated with RHEL 3 (3.0.0-14.3E), for example, you can download the Samba source RPM from a Red Hat Rawhide server at ftp.redhat.com or one of the mirrors listed at www.redhat.com/download/mirror.html.
If you have a high-speed connection, downloading Red Hat operating system CD-ROMs is fairly easy. If you've purchased Red Hat Enterprise Linux, follow the Red Hat Network download instructions. If you want to download the Red Hat Linux 9 or Fedora Installation CDs, just connect to ftp.redhat.com or one of the many mirrors such as Tucows Linux (www.tucows.com) or www.linuxiso.org, and start your download. If you're downloading a third-party rebuild of RHEL 3, navigate to their Web sites for more information. Since FTP is optimized for file transfer, FTP clients are the best way to download a Linux distribution.
There are two ways to download and prepare Red Hat Installation files: as individual files or as ISO packages. You can install from ISO packages on a hard drive. You can also install from ISO packages or a directory of RPM files on an HTTP, FTP, or NFS server.
Once you've downloaded the installation files or ISOs, you're ready to install the Red Hat operating system, possibly with the help of the appropriate boot disk as described later in this chapter.
If you have 2GB of available disk space, you can download the Red Hat operating system installation files. Create a RedHat directory or subdirectory on your hard disk, and copy the files from the /RedHat directory on the FTP server. I'll show you shortly how you can use this to set up a network installation server.
On your computer, direct the download to a /RedHat directory (or subdirectory). Organize the files in the /RedHat directory with the same subdirectories that you can find on a Red Hat installation CD. Make sure to include both the /base and /RPMS subdirectories. When you perform the download, make sure you also copy the hidden .discinfo file on the first installation CD.
An ISO is a single file that is associated with a large package of files, usually on a CD. Once you download an ISO, you can use a number of tools to extract the files to a CD-ROM. There are four binary installation ISOs associated with Red Hat Enterprise Linux 3. Alternatively, the third-party rebuilds (as of this writing) have consolidated the RHEL 3 software on three binary installation ISOs.
As long as you have a high-speed connection, it's easy to download the appropriate ISOs. I describe the lftp client in Chapter 7. Once you've downloaded the three Red Hat installation ISOs, use the tool of your choice to extract the contents to a writable CD. For example, the following command records the /tmp/RedHat/rhcd1.iso file, at 2x speed, to a blank writable CD on the first CD drive on your computer:
# cdrecord -v speed=2 dev=0,0,0 /tmp/RedHat/rhcd1.iso
If you need more information on recording CDs, refer to the CD-Writing HOWTO available from www.tldp.org. Alternatively, you can mount the ISO as if it were a CD. For example, the following command mounts the aforementioned ISO file:
# mount -t iso9660 -ro loop /tmp/RedHat/rhcd1.iso /mnt/cdrom
You don't even need to extract the files from the ISO. Just use the /mnt/cdrom directory as if it were a real CD.
It's easy to check the integrity of each installation CD. Reboot your computer with the first Red Hat Enterprise Linux installation CD. Type linux mediacheck at the prompt; the RHEL 3 installation program takes you to the screen shown in Figure 2-1 where you can test each CD.
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As you prepare for the RHCE or RHCT exams, remember to think in terms of what is practical. While it is important to know how to download and set up a Red Hat installation CD, it wouldn't be practical for a group of test candidates to all be downloading the Red Hat installation CDs during an actual exam.
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