Red Hat Enterprise Linux

Red Hat Enterprise Linux ( RHEL) [ ɹɛd HAET entə (r ) ˌ praɪz linʊks ] is a popular Linux distribution, which has the company Red is produced and is tuned to the enterprise market. It applies in this area as a leader among Linux distributions and enjoys a lot of support from independent software vendors.

  • 4.1 Red Hat Enterprise Linux 6.x
  • 4.2 Red Hat Enterprise Linux 5.x
  • 4.3 Red Hat Enterprise Linux 4.x, 3.x
  • 4.4 Red Hat Enterprise Linux 2.x

History of Distribution

RHEL has evolved from the former Linux distribution Red Hat Linux ( RHL ) emerged and was first published on 17 May 2002. The aim was to develop a specifically tailored for business customers distribution with appropriate support and training services. As Red Hat in September 2003, the retail product Red Hat Linux Fedora abandoned in favor of the project, RHEL remained the only Red Hat Linux distribution marketed left. Red Hat uses the community work of the Fedora project (which it is sponsoring a major ) to develop this further to RHEL. Red Hat Enterprise Linux 6.x ( RHEL) based on Fedora 12


RHEL exists in different variants. These include the server versions with the version entry server (ES) and Advanced Server (AS). The Desktop family includes the Red Hat Desktop (RHD ) and Red Hat Enterprise Linux WS ( workstation). For these products is update support via Red Hat Network possible.

Special features of Red Hat Enterprise Linux distribution

Red Hat Enterprise Linux distinguishes itself with a number of features from other distributions:

Enterprise operating system

RHEL is an enterprise operating system, so an operating system that is geared to the needs of large enterprises. As an enterprise operating system, therefore it is designed for durability and long maintenance cycles. You can use RHEL up to ten years to have to migrate without packages and software versions, so it is suitable for commercial use. For RHEL offer great software companies such as Oracle or SAP certificates that guarantee that the software works fine on RHEL, which also applies to large server manufacturers. Enterprise operating systems one finds therefore mostly on workstations and servers where a extremely stable operation is required. ( For example, in science, research, stock exchange, military or space. )

Life cycle

The life cycle of a RHEL version is ten years. During this period, the availability of updates and patches from Red Hat guaranteed. The first three RHEL versions initially recorded on a seven-year life span. By purchasing an Extended Life Cycle Support License ( ELS) can be obtained for RHEL 3 and 4, a supply of hotfixes for another 3 years.

Software Management

Red Hat Enterprise Linux is installed with a graphical installer called Anaconda, which is easy to use even for beginners. In the Software Management uses Red Hat Enterprise Linux yum on the package manager RPM and software management. Applications and system components is done by finding online on a repository server, by downloading a RPM package and installed. For a general configuration of the system, the system-config- * programs available, each of which also have graphical user interfaces. The system-config -* tools are according to the usual Red Hat and programmed Fedora principles - these specify that " management tools " (support tools for system administration ) only targeted fulfill a single task and no exclusive control over configuration files need. Administrators of a system must be in spite of management tools able to make any changes in the configuration files manually.

Software repository provider

Repositories of other providers usually have different objectives or other licensing policy as RHEL. Noteworthy here are Dag Wieers, RPM Fusion, RPMForge and ATrpms. These sources are not always compatible with each other. In addition, more and more software projects and companies, such as the Mono project, the GStreamer project, Skype or Adobe, own repositories available.


EPEL (Extra Packages for Enterprise Linux) is a well maintained by the Fedora Project repository that provides ported packages of software that is included in Fedora itself, but not in RHEL, CentOS or Scientific Linux. Because this enterprise distributions are developed on the basis of Fedora, only very small adjustments to the packages are usually necessary. Thus EPEL extends the enterprise distributions to many applications and drivers there are disclaimed. Since EPEL dependent solely on the use of the community, give Red Hat and the Fedora Project for EPEL packages no guarantees, support or certifications, as is common for packages in the official RHEL repository.


RHEL fully integrates the kernel extension SELinux, so as to allow Mandatory Access Control. Apart from the actual SELinux core also a graphical program is supplied with analyzing the activities of SELinux and can be further processed.

The aim of the SELinux integration is that particular RHEL 5 should comply with the certifications EAL4 and Labeled Security Protection Profile under the Common Criteria standard.

Open Source Assurance

Red Hat offers for the RHEL distribution of insurance that protects against claims for intellectual property in the Software. This is possible because of software patents. For example, protected the insurance against possible lawsuits the company SCO, the parts of the intellectual property claimed by Linux (see SCO against Linux).

LSB certification

Early versions of RHEL Version 5 LSB 3.2 certified, as was raised from RHEL 5.6 and RHEL 6 for the support on LSB 4.0. Earlier versions of RHEL are certified to older LSB standards.

Versions and architectures supported

Red Hat Enterprise Linux 6.x

Red Hat Enterprise Linux 6.x is available in two versions (server or workstation) and supports the following architectures:

Workstation and Server:

  • X86 i386 compatible (32 bit)
  • X86 -64 - AMD64 and Intel EM64T (64 bit)


  • IBM Mainframe (31 /64 bit, IBM S/390 and IBM zSeries )
  • PowerPC (32 /64 bit, Apple, IBM iSeries, IBM pSeries )

Red Hat Enterprise Linux 5.x

Red Hat Enterprise Linux 5.x is available in two variants (server or workstation) and supports the following architectures:

Workstation and Server:

  • X86 i386 compatible (32 bit)
  • X86 -64 - AMD64 and Intel EM64T (64 bit)


  • Intel Itanium IA -64 ( 64 bit, Hewlett -Packard, SGI)
  • IBM Mainframe (31 /64 bit, IBM S/390 and IBM zSeries )
  • PowerPC (32 /64 bit, Apple, IBM iSeries, IBM pSeries )

Red Hat Enterprise Linux 4.x, 3.x

Red Hat Enterprise Linux 3.x and 4.x were developed in three variants: Advanced Server (AS, max 16 CPUs, up to 64GB RAM. ) Enterprise Server (ES, 2 CPUs, 8GB Ram ) or workstation (WS, 2 CPUs, 64GB Ram ), it supports the following architectures:


  • X86 i386 compatible (32 bit)


  • X86 -64 - AMD64 and Intel EM64T (64 bit)
  • Intel Itanium IA -64 ( 64 bit, Hewlett -Packard, SGI)


  • IBM Mainframe (31 /64 bit, IBM S/390 and IBM zSeries )
  • PowerPC (32 /64 bit, Apple, IBM iSeries, IBM pSeries )

Red Hat Enterprise Linux 2.x

Red Hat Enterprise Linux 2.x there were in the following versions:

  • Red Hat Enterprise Linux AS ( Advanced Server ) - i386, IA -64
  • Red Hat Linux Advanced Workstation - IA -64
  • Red Hat Enterprise Linux ES - i386
  • Red Hat Enterprise Linux WS - i386

Other distributions on the same basis

Although Red Hat source packages of RHEL distributions freely provides the net, it is directly from Red Hat no freely available RHEL boot media or images, RHEL, as, for example, the (not RHEL based ) competitive product SUSE Linux Enterprise server only be purchased in conjunction with support contracts. To be able to offer a freely available, RHEL -compatible Linux, such as CentOS or Scientific Linux projects have emerged. Since all the source packages are ready for RHEL distributions in the network, these projects can compile all freely available packages and provide at his own boot images and installation media. The goal is, usually with only minor changes to produce a distribution that is fully compatible with RHEL and consists solely of freely available software. As a rule must therefore licensing reasons individual packages (eg, Adobe Reader, Flash Player) are removed from the distribution. Conversely, additional packages can be added, which are also free and create no obligation to purchase licenses or support contracts with them.

Examples of distributions based on RHEL, are: CentOS, ClearOS (formerly ClarkConnect ), Endian Firewall, Scientific Linux, White Box Linux, and X / OS Linux.

Areas of application

RHEL is used in addition to Scientific Linux and Debian on the International Space Station, as NASA announced.

RHEL has been selected at the Department of Defense as the standard platform for server-based applications, Web services, databases, network security, and the like. RHEL is used in the U.S. Army in numerous places. The Ministry of Defence in 2005 to the largest customers of the company Red Hat.

The National Aviation Authority (FAA ) of the USA in spring 2006 migrated completely to RHEL. This allowed public funds to the tune of 15 million U.S. dollars will be saved. The FAA previously used Windows, but a very expensive proprietary UNIX platform. With RHEL, problems could be solved with the scalability, improve efficiency, and ensure the required high availability of the systems. The security of up to 8,000 aircraft that can be on the road simultaneously monitored by the FAA airspace depends largely on the availability of the IT infrastructure of the FAA, the authority can not allow errors or failures.