Userspace Applications

 < Free Open Study > 



Red Hat ships a lot of software with their system. Generally, this is true of most Linux distributions; they tend to be very complete software packages. On a commercial system such as Microsoft Windows or a commercial Unix, you typically must pay for things such as compilers, office productivity software, and web servers in addition to the base operating system; but this type of software for Linux systems is usually just as free as the operating system itself. This section describes the software that ships with a Red Hat Linux system.

Generally, Red Hat Linux contains the usual fare common to Linux systems:

  • emacs text editor (as well as its cousin, xemacs)

  • gcc compiler suite

  • Apache web server

  • Samba software for Windows-compatible SMB file sharing

Red Hat follows the "leading edge" without being "bleeding edge" (most of the time, anyway). For example, back in the early days, theirs was one of the first distributions to switch to the GNU libc package from the original libc5 package typically used with Linux. Red Hat also follows the latest kernel; for example, Red Hat Linux 7.1 shipped with the 2.4.x series of kernels shortly after they were released. Version 7.3 also included the latest XFree86 and KDE desktop, even making use of their support for antialiased fonts, even though that feature was still technically beta. On the other hand, Red Hat's quality assurance process does sometimes prevent them from releasing "undercooked" software. Testing on the 2.4 series of kernels, for example, exposed a few problems with the ReiserFS journaling filesystem, preventing its default inclusion in Red Hat Linux 7.1.

Red Hat Linux, like most distributions, contains a large amount of software. Some of it is considered core to the distribution, while some of it is considered mainly of interest to so-called power users. There is so much software, in fact, that the whole distribution (including optional packages) now consists of three compact discs, with even more for source code and documentation! To get a feel for what you actually get with Red Hat Linux, simply look at the lists of RPM files on the installation CDs. The remainder of this section discusses how Red Hat organizes their distribution as follows:

  • Core distribution

  • Source code and documentation CDs

  • Red Hat Linux editions

Understanding the Core Distribution

The core Red Hat Linux distribution contains software that is frequently used by many or most users. As recently as version 6.2, Red Hat Linux could fit on a single CD. However, due to the inexorable increase in size of existing packages and the introduction of new packages, the core distribution now consists of three CDs, not including the source code.

Of course, the more discs a user has to deal with, the more confusing installation and maintenance become. For example, there are so many packages now that performing a custom installation and selecting individual packages can take quite a while, even for expert users, simply due to the sheer number of packages available. To ameliorate these difficulties, Red Hat identified some common profiles of system usage, such as Workstation, Web Server, File Server, and so on. Each profile is oriented toward a different usage pattern and is associated with a list of packages for that profile. Red Hat's installation program, anaconda, allows users to select one or more of these predefined profiles to produce a configuration that meets most of their needs. The issue, of course, is that these configurations are inevitably someone else's idea of what a system of that type should contain. However, even if most users end up customizing a default configuration, at least they are starting points.

For users (generally network and system administrators) who need to install many instances of the same configuration, Red Hat provides a package known as kickstart that allows these administrators to essentially create their own "canned" configurations. Administrators can then set up a server machine containing the software packages and use a floppy disk to boot each target machine. The target machines then fetch their packages from the server for the installation. Additionally, the up2date software can be customized to work with a server local to a network, so that administrators can easily upgrade their installations according to their own needs. (Of course, Red Hat does not provide a customizable version of the up2date server, so work would have to be done to obtain or create one.)

Source Code and Documentation CDs

The core distribution Red Hat Linux CDs contain typical software, for both desktop and server applications. However, some users need additional information on the distribution and the software included with it, while other users may need access to the original source code for the system (which is almost always available, since this is open source software). To accommodate these needs, Red Hat Linux 7.3 includes not only the three installation CDs, but also two source code CDs and a documentation CD. That's a total of six CDs, for those keeping track.

Red Hat Linux Editions

Red Hat actually produces several different editions of their distribution. Each edition has a different focus, and some editions contain some non–open source commercial software add-ons. The editions tend to change a bit from release to release, but as of version 7.3, they are as follows:

  • Red Hat Linux Personal

  • Red Hat Linux Professional

  • Red Hat Linux Advanced Server

The Personal edition is suitable for home users and individuals. The Professional edition is for more corporate-oriented and other larger-scale users, and it contains some tools and software that are useful in those contexts. The Advanced Server edition, meanwhile, contains various high-end features and software, such as the ability to cluster servers for web sites, databases, and other server tasks. In addition, the Advanced Server edition includes premium support options. Red Hat also publishes distributions for several non-i386 architectures, such as IBM S/390 mainframes and Intel's Itanium processor.

Finding Additional Software

Eventually, almost every user will find that he or she needs software not included with Red Hat's distribution. In these cases, users usually end up going to the Web to search for software. There are, however, several software applications that make this process easier. The Debian package management tools actually integrate searching for packages over the network and automatically downloading and installing them; RPM doesn't support this inherently, but there are several tools available that add this behavior.

One such tool is rpmfind. This tool is both a program used to search for, download, and install RPM packages and a web site that can be used for convenient searches for RPMs. Both the tool and the web site are maintained by Daniel Veillard of the World Wide Web Consortium (W3C). The web site is located at http://www.rpmfind.net. The rpmfind tool on Red Hat Linux systems can be viewed as a sort of last resort; most users will (but need not, of course) treat Red Hat itself as the primary source of RPMs via up2date, simply as a matter of convenience. However, for those cases where Red Hat doesn't maintain official RPMs for a given piece of software, rpmfind can be very useful indeed.



 < Free Open Study > 



Tuning and Customizing a Linux System
Tuning and Customizing a Linux System
ISBN: 1893115275
EAN: 2147483647
Year: 2002
Pages: 159

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net