Red Hat Enterprise Linux 5 Administration Unleashed

126CHAPTER 5Working with RPM Softwareto customize which parts are necessary for the system’s usage. For example, the GNOMEgraphical desktop is divided into many packages that contain parts of the overall desktop.For example, the gnome-menus package contains the files necessary for the desktop menus,while gnome-panel provides the files necessary for the panels. Some GNOME packagessupply additional functionality not absolutely necessary for the desktop to function properly.Dividing the desktop until these specialized packages allows the administrator toonly install the software essential for each computer.A proper RPM file should follow a specific naming convention:--..rpmFor example, pciutils-2.2.1-1.2.i386.rpm is the RPM filename for the 1.2 release ofversion 2.2.1 of the PCI utilities software package built for the i386 architecture.In our example, 2.2.1 is the version of pciutils, and 1.2 is the build version. The versionnumber is similar to what you might have encountered with other software. The majorversion number is incremented when major features are added or it becomes incompatiblewith previous versions. It usually maps to specific package and distribution independentupstream version numbers. The minor version number is usually distribution dependentand changes for bug fixes, minor feature additions, and general maintenance. The releaseversion starts at 1 for each version number change and is incremented every time thatversion is built for Red Hat Enterprise Linux. This small change allows the developer andusers to know the package has been rebuilt while still keeping the version number the same.The next part of the RPM filename is the architecture for which the package is built. Becausedifferent processors must use different software libraries, have different system calls, andutilize different optimizations, software must be built with the proper version of the compilercompatible with the architecture. There are some exceptions such as software written in aninterpreted language such as Python, which is not compiled. For software written in this typeof language, the correct version of the software that interprets the code must be installedwhile the RPM package that installs the code can be platform-independent. The mostpopular architectures abbreviations used by RPM are explained in Table 5.1.TABLE 5.1 System Architectures Used by RPMArchitecture Descriptionnoarch Architecture-independent, can run on any architecturei386Generic build for a 32-bit x86 systemi586Sometimes used when building kernels for older x86 processorsi686Intel® Pentium® II, Intel Pentium III, Intel Pentium 4, AMD® Athlon, andAMD Duron systems (Most RPMs for these architectures are built using thei386 architecture, with the kernel for these architectures being built with thei686 for optimal performance.)x86_64 64-bit processors such as AMD Athlon64, AMD Opteron, and Intel EM64Tia64Intel® Itaniumppc32-bit IBM® POWER, IBM eServer pSeries®, and IBM eServer iSeriess390x 64-bit IBM eServer System z