Configure the YUM server and client in RHEL5

Before talking about YUM, let's take a look at what RPM is? RPM is the abbreviation of RedHatPackageManager. As the name suggests, this software management program was developed by RedHat, and of course there are many similar software management programs. However, RPM is easy to use, so it has become the most popular software management program. RPM is a set of management programs that install the required software to the Linux system in a database record manner. The biggest feature is that the software to be installed is compiled first (if necessary

Before talking about YUM, let's take a look at what RPM is? RPM is the abbreviation of RedHat Package Manager. As the name suggests, the software management program was developed by Red Hat, and of course there are many similar software management programs. However, RPM is easy to use, so it has become the most popular software management program.

RPM is a set of management programs that install the required software to the Linux system in a database record manner. The biggest feature is that the software to be installed is compiled first (if needed) and packaged, and pre-configured database records in the packaged software are used, record the other software that must be installed when the software is to be installed. When the software is installed in Linux, based on the data recorded in the software, RPM first queries whether other software on Linux is satisfied. If yes, It is installed. If not, it is not installed.

The biggest problem with the RPM package installer is that, since the RPM program is packaged data, that is, the data in it has been compiled, during installation, you must first install the host environment. The installation environment for this software must also appear on the current host. If you have experience installing RPM, It is a headache. YUM can solve this problem well.

YUM is Yellow dog Updater, short for Modified. It is a plan initiated by Duke University to solve the problem of RPM dependency, it is convenient for users to install and upgrade software. It is particularly noted that YUM is only used to solve RPM dependency problems, rather than other software installation modes. Of course, in addition to YUM, we can also implement APT (Advanced Package Tool, a software management Tool developed by debian ).

In fact, the operating principle of YUM is not complex. The dependency between the software is recorded in the header of each RPM software. If you can record the content of this header and analyze it, you can know which basic software needs to be installed before each software is installed. That is to say, on the server, analyze all RPM files with an analysis tool, and then record the analysis as long as the files recorded are queried during installation or upgrade, all associated software can be known. The basic workflow of YUM is as follows:

Server: stores all RPM software packages on the server, and analyzes the dependency between each RPM file with relevant functions, record the data into files stored in a specific directory on the server.

Client: If you need to install a software, download the dependency file recorded on the server (via WWW or FTP) and analyze the record data downloaded from the server, then obtain all the relevant software and download it all at a time for installation.

After RHEL 5 is installed, when "Applications à Add/Remove Software" is opened in GNOME, for example, why cannot it be used? No, because only the normally configured YUM client can install the software here.

The following describes how to configure the YUM server and client respectively.