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Written and Provided by Expert Reference Series of White Papers An Overview of the Red Hat Enterprise Linux 4 Product Family 1-800-COURSES www.globalknowledge.com An Overview of the Red Hat Enterprise Linux 4 Product Family Abstract This white paper provides information on the family of Red Hat Enterprise Linux and Red Hat Desktop products. It describes the family'sfeatures and benefits and also gives a brief overview of the open source layered products designed for Red Hat Enterprise Linux environments. Revision 4b. February 2005 Copyright © 2005 Red Hat, Inc. All rights reserved. “Red Hat” and the “Shadowman” logo are registered trademarks of Red Hat, Inc. in the US and other countries. Linux is a registered trademark of Linus Torvalds. All other trademarks referenced herein are the trademarks of their respective owners. WHP77853US 02/05 Table of Contents Red Hat Enterprise Linux Family Overview......................................................3 Developing the Distribution...............................................................................3 Creation of Fedora........................................................................................3 Creation of Red Hat Enterprise Linux..........................................................4 Red Hat Enterprise Linux Products...................................................................5 Red Hat Enterprise Linux AS.......................................................................6 Red Hat Enterprise Linux ES.......................................................................6 Red Hat Enterprise Linux WS......................................................................6 HPC with Red Hat Enterprise Linux WS......................................................7 Red Hat Desktop..........................................................................................7 Product Summary.........................................................................................8 Example Configuration......................................................................................9 Technical Features............................................................................................9 Read Copy Update (RCU)...........................................................................10 Selectable I/O elevators...............................................................................10 Object­Based Reverse Map VM...................................................................11 Generic logical CPU scheduling...................................................................12 Block I/O subsystem.....................................................................................12 Sys_epoll() support......................................................................................12 Support for larger server systems................................................................13 Upward Compatibility...................................................................................13 File System Performance enhancements....................................................13 Red Hat Desktop..........................................................................................13 Security.........................................................................................................15 Auditing.........................................................................................................17 Compiler and Library Buffer Management...................................................17 Advanced GLIBC memory corruption checks.........................................17 Printf format string exploit prevention.....................................................17 GCC buffer bound checking....................................................................17 Standards Compliance.................................................................................17 Development Environment...........................................................................18 Storage Subsystem......................................................................................18 Automounter.................................................................................................19 Networking....................................................................................................19 Feature Summary.........................................................................................19 Support Services...............................................................................................20 Red Hat Network...............................................................................................21 Application Availability.......................................................................................22 Hardware Availability.........................................................................................23 Benchmarks.......................................................................................................24 Layered Products for Red Hat Enterprise Linux...............................................25 Red Hat Global File System.........................................................................25 Red Hat Cluster Suite...................................................................................26 Comparing Red Hat Global File System and Red Hat Cluster Suite..........26 Red Hat Application Server..........................................................................28 Red Hat Developer Suite..............................................................................28 Summary............................................................................................................29 An Overview of the Red Hat Enterprise Linux Version 4 Product Family 2 Red Hat Enterprise Linux Family Overview Since 2002, Red Hat has steadily expanded its range of open source, commercially­focused operating system and middleware products. These products provide the industry' s premier Linux environment for commercial deployments. The operating system products, sold by annual subscription under the name Red Hat Enterprise Linux, have been rapidly adopted and supported by a wide range of Independent Software Vendors (ISVs) and Original Equipment Manufacturers (OEMs). They offer excellent performance, scalability, and security, and a comprehensive array of services delivered by Red Hat and its partners. As a result, Red Hat Enterprise Linux solutions, deployed on certified commodity hardware and running a wide variety of enterprise­caliber applications, are delivering the capabilities of traditional proprietary UNIX systems but at significantly lower cost. The initial releases of the Red Hat Enterprise Linux family, versions 2.1 and 3, are described in earlier white papers (see An Overview of the Red Hat Enterprise Linux product family, March 2003 and June 2004). This paper describes the latest release of the family,version 4, which was delivered in February 2005. Developing the Distribution As the leading provider of open source software solutions, Red Hat implements a sophisticated development process to create the Red Hat Enterprise Linux family of products. The process has two major phases: Creation of Fedora The Fedora Project is a Red Hat­sponsored and community­supported open source project. It serves as a proving ground for new technology that may eventually make its way into commercial Red Hat products. The goal of the Fedora Project is to work with open source development communities to build a complete, general purpose operating system exclusively from open source software. All development is done in a public forum. Fedora Core releases are issued about 2­3 times a year and are available for free download from Red Hat servers and over 200 mirror sites worldwide. The leading­edge, rapidly­changing nature of Fedora makes it impractical for use in commercial environments, and it is not formally supported by Red Hat or its ISV/OEM partners. The first stage in the process of creating Fedora requires defining the set of packages to be used. The number of packages to choose from in the open source arena is huge. A single code repository such as Sourceforge (www.sourceforge.net) alone has over 90,000 packages and almost 1,000,000 registered users. So package selection is a complex exercise, resulting in approximately 1500­2000 being selected. These packages are then built and integrated into a complete system, a process that requires significant engineering resources including new development, bug fixes, creation of an installation program, management utilities, documentation, and An Overview of the Red Hat Enterprise Linux Version 4 Product Family 3 the project management necessary to coalesce a large group of distinct projects into a usable whole. Fedora has established itself as a highly successful free distribution and widely regarded as the de facto standard platform for applied software research and development. Creation of Red Hat Enterprise Linux While the creation of Fedora can be considered a first stage distillation of open source software projects into a complete distribution, the creation of Red Hat Enterprise Linux takes this process another step, the second stage distillation. In the Fedora arena, software packages enjoy significant public exposure and mature rapidly. Red Hat creates the Enterprise Linux family of products by selecting approximately 1000­1500 of the most stable Fedora packages. Those that are not selected are either not sufficiently stable, not necessary for a commercially­focused product, or provide duplicate capabilities. (For example, Fedora may include half a dozen web browsers each of which provides different quality and features. Only the best one or two will be selected for inclusion in Red Hat Enterprise Linux.) Red Hat Enterprise Linux releases are provided approximately every 18 months and supported by Red Hat and its partners for seven years. During this time, APIs/ABIs are maintained stable so that applications continue to work for the life of the product. It is the stability offered by Red Hat Enterprise Linux that makes it practical for ISV/OEM partners to certify their products with it. During the extended release cycle Red Hat: • Works closely with partners and customers to ensure that the features and technologies they require are included (for example: database support features, performance features, I/O support and device drivers, etc). • Performs extensive quality assurance testing with formal Alpha/Beta programs. • Performs necessary internationalization, including translations. • Develops additional (multi­lingual) documentation. • Builds products for the required system architectures. • Ensures that features required for necessary standards certifications (security and applications such as NIAP/CC and ISO) are provided. • Integrates technologies required by Red Hat'slayered products (for example, clustering). Figure 1 shows the two stage distillation process from the community projects on the outside to Fedora as the unsupported, rapidly­changing vehicle for technology development to Red Hat Enterprise Linux as the stable, mature, commercially­focused distribution in the center. An Overview of the Red Hat Enterprise Linux Version 4 Product Family 4 Figure 1: Distillation process from the Community to Red Hat Enterprise Linux Red Hat Enterprise Linux Products The Red Hat Enterprise Linux family has been designed to cover the full spectrum of corporate operating environments in a simple and consistent manner. The family is comprised of four products, two designed for server systems, two designed for client systems. There is a high level of commonality across the products, thereby ensuring that application support, user environments, and management tools are consistent. The products are primarily differentiated by the level of system architecture support, system size, and service offerings. Red Hat Enterprise Linux supports multiple hardware architectures including: • Intel x86­compatible (32­bit) • Intel Itanium2 (64­bit) • Advanced Micro Devices AMD64 (64­bit) and Intel EM64T • IBM POWER series (eServer iSeries and eServer pSeries) • IBM Mainframe (eServer zSeries and S/390) Perhaps the most important feature of Red Hat' s multi­architecture development process is that all implementations are built from identical source code. The primary benefit of this commonality is that all the products are completely compatible, regardless of architecture. This assists ISVs in supporting their applications on multiple architectures and also simplifies system administration and product support. An Overview of the Red Hat Enterprise Linux Version 4 Product Family 5 The individual members of the Enterprise Linux family remains unchanged from version 3: • High­end server: Red Hat Enterprise Linux AS • Entry/mid­level server: Red Hat Enterprise Linux ES • High­end client: Red Hat Enterprise Linux WS • General purpose client: Red Hat Desktop An important feature of the family is that it is cleanly subsetted. That is, all the features of a low­end product are also available in a high­end product. Therefore, upgrades from one family member to another do not result in the loss of features, and server products can be deployed in client environments. The following sections outline the major features of each Red Hat Enterprise Linux family member. Red Hat Enterprise Linux AS Red Hat Enterprise Linux AS (“advanced server”) is the top­of­the­line enterprise Linux solution, designed for large departmental and datacenter server deployments. Red Hat Enterprise Linux AS is the only family member that supports IBM POWER and zSeries/S­390 systems and is available with Standard and Premium Edition support. Red Hat Enterprise Linux AS is best suited for systems with more than 2 CPUs or more than 16 GB of main memory. Typical Red Hat Enterprise Linux AS deployments would be used to support: • Medium to large­scale databases and database applications • Large web and application servers • Corporate applications such as CRM, ERP, and SCM Red Hat Enterprise Linux ES Red Hat Enterprise Linux ES (“entry/mid server”) provides an entry­level and mid­range server operating system for the Intel x86, EM64T, Itanium2, and AMD64 markets. It supports 1­2 CPU systems with up to 16 GB of memory and is suitable for a wide range of applications–ranging from the edge­of­ network to medium scale departmental deployments. It includes the same capabilities as Red Hat Enterprise Linux AS and is differentiated by its support for smaller systems and lower price. Enterprise Linux ES is available with Basic Edition and Standard Edition support. Typical Red Hat Enterprise Linux ES deployments are used to support: • Corporate web infrastructures • Edge­of­network applications (DHCP, DNS, firewalls, etc.) • Mail and file/print serving • Small­medium database and departmental applications Red Hat Enterprise Linux WS Red Hat Enterprise Linux WS (“workstation”) is the high­end desktop/client An Overview of the Red Hat Enterprise Linux Version 4 Product Family 6 member of the Red Hat Enterprise Linux family. Red Hat Enterprise Linux WS supports 1­2 CPU 32­bit and 64­bit Intel and AMD systems (x86, EM64T, Itanium2, and AMD64), and is ideal for “power user,” software development, and technical applications such as virtualization/rendering (CAD/CAM, EDA, etc.). It includes a full suite of desktop productivity applications for tasks such as document creation, email, instant messaging, and web browsing. While Red Hat Enterprise Linux WS is based on the same software core as the server products, it does not include a number of network server applications (such as DNS and DHCP). Therefore it is suitable only for use in client environments. Enterprise Linux WS is available with Basic Edition and Standard Edition support. HPC with Red Hat Enterprise Linux WS Red Hat Enterprise Linux WS is usually the most cost effective Enterprise Linux product for use in High Performance Computing (HPC) environments. In these environments it is deployed in a headless workstation mode without a monitor, keyboard or mouse. A few common HPC­related packages are included in the Enterprise Linux family such as PVM and LAM. Red Hat Desktop Red Hat Desktop is the high­volume desktop/client member of the Red Hat Enterprise Linux family. It supports 32­bit Intel x86 and 64­bit Intel EM64T and AMD64 systems with one CPU and up to 4 GB of main memory. It provides the same software functionality as Red Hat Enterprise Linux WS but for smaller systems and at a lower price point. Red Hat Desktop is provided in multi­unit packages bundled with a Red Hat Network (RHN) Proxy or Satellite Server. The RHN server is used to efficiently perform desktop management functions such as the installation of updates and security patches. An Overview of the Red Hat Enterprise Linux Version 4 Product Family 7 Product Summary Table 1: Summary of the Features of the Red Hat Enterprise Linux family Feature 1 2 3 Red Hat Enterprise Linux AS Red Hat Enterprise Linux ES Red Hat Enterprise Linux WS Red Hat Desktop Supports Intel x86, EM64T, and AMD64 systems Yes Yes Yes Yes Supports Intel Itanium2 systems Yes Yes Yes No Supports IBM POWER S/390 & zSeries systems Yes No No No 2 2 1 Maximum CPUs supported1 ­2 Maximum memory supported ­ 16 GB ­ 4 GB Subscription to Red Hat Network 1 year 1 year 1 year 1 year 12x5 services available Yes Yes Yes N/A3 24x7 services available Yes No No N/A Includes desktop applications Yes Yes Yes Yes Includes network server applications (e.g.: dhcp; dns) Yes Yes No No Supported by leading ISV applications Yes Yes Yes Yes A processor chip with multi­core or hyper­threaded processing elements is counted as one CPU There is no subscription support limit, although a maximum may be imposed by hardware, software, or architectural limitations. Refer to www.redhat.com for specific details. Offered with 24x7 Help Desk Escalation Support; Red Hat Network Proxy Server provided with Premium Edition support. An Overview of the Red Hat Enterprise Linux Version 4 Product Family 8 Example Configuration Figure 2 shows a typical commercial intranet deployment with many small/medium servers, several high­end servers, and a High Performance Computing (HPC) compute farm. Figure 2: Typical Commercial Intranet Deployment. The graphic shows how Red Hat Enterprise Linux family products can be deployed across a corporate IT infrastructure. Red Hat Enterprise Linux ES proves ideal for providing network services such as web servers, mail servers, file/print servers, and background network management services such as DHCP and DNS. Meanwhile Red Hat Enterprise Linux AS is used to host large­scale server applications and corporate databases. Red Hat Enterprise Linux WS is used for technical or development workstations and is also suitable for an HPC compute farm for services such as data­mining or financial modeling. Lastly, Red Hat Desktop meets the needs of the general purpose desktop user. Note that the entire environment can be provisioned, updated, and managed using the Red Hat Network Proxy Server that is included in the configuration. Technical Features A primary feature of Red Hat Enterprise Linux products is that they include technologies and features that provide a premier enterprise­quality computing environment. Features are selected on the basis of their appropriateness for commercial deployment (such as support for large SMP systems) and must also exhibit a high degree of reliability. This is significantly different from most Linux distributions where the focus is usually on providing the latest features as soon as possible (often at the expense of stability) and concentrating on serving low­end markets. Red Hat Enterprise Linux v.4 was developed in close collaboration with Red Hat'smajor customers and ISV/OEM partners to ensure that it provides the An Overview of the Red Hat Enterprise Linux Version 4 Product Family 9