A base Red Hat Enterprise Linux server provides fully-virtualised guest support for Red Hat Enterprise Linux 3, 4, and 5. Third party operating systems may also be hosted. Additionally, offering the highest levels of performance, para-virtualised guest operating system support for Red Hat Enterprise Linux 5 and version 4 Update 5 is available.

Fully-virtualised guest support requires hardware features provided by Intel Virtualisation Technology and AMD-V processors. Para-virtualised guests can be configured on any 32-bit x86 (with PAE support), 64-bit x86, or Itanium2 system.

With Red Hat Enterprise Linux Advanced Platform the number of guest operating systems that may be hosted is unlimited, constrained only by physical hardware resources.

With Red Hat Enterprise Linux a total of four guest operating systems are supported.

When running on a Red Hat Enterprise Linux host, Red Hat Enterprise Linux guests do not require separate subscriptions. Guests are automatically entitled to subscription services through the subscription to the Red Hat Enterprise Linux host. Third party operating system guests must be licensed according to the practices of the respective vendor. For information on Red Hat Enterprise Linux guests deployed on third party virtualisation platforms, please refer to your local Red Hat sales representative.

Benefits: Virtualisation systems provide many attractive capabilities, including:

• Reduced costs through server consolidation, coupled with savings in power, cooling, maintenance and third party software.
• Improved application availability and response due to flexible resource management.
• The ability for IT departments to innovate, responding to new business demands quickly and at minimal cost.

Comprehensive management capabilities for virtualisation are provided, including:

• libvirt: a programmable management library that provides hypervisor independence
• virsh: a scriptable command shell
• Red Hat Network enhancements that manage guest entitlements
• virt-manager: a graphical interface for virtualisation functions (create, start, stop, suspend, resume, monitor, etc.)
• Red Hat Enterprise Linux Advanced Platform includes Conga, a new management utility that provides web-based control of storage, applications, and servers in small and large multi-cluster environments.

Benefits: Easy, comprehensive management of virtualised environments.

Red Hat Enterprise Linux supports the following system architectures and deployment environments:

Example server environments:

• Standalone server
• Large SMP "scale-up" server
• Blade server
• High availability cluster server
• Rack server
• Fault tolerant server
• HPC "scale-out" server
• Mainframe server

Supported Architectures:

• Intel and AMD x86/x86-64
• Intel Itanium2
• IBM POWER
• IBM System z and S/390

Example Applications	Benefits
File/Print server	Provides file and print serving services to Microsoft® Windows® clients, with Active Directory integration and new support for nested groups. Provides print and file service services for UNIX® environments, with NFSv4 and AutoFS support, including authenticated binds and shared maps.
Web server	The Red Hat Enterprise Linux Apache-based http server provides high performance, excellent security, and a comprehensive set of optional plug-ins.
Application server	Apache Tomcat servlet container, included in Red Hat Enterprise Linux, is the reference implementation, powering large-scale, mission critical web applications.
Database server	Choose from the MySQL and PostgreSQL open source databases included in Red Hat Enterprise Linux or a third party product from vendors such as Ingres, Sybase, or Oracle.
Network infrastructure server	Red Hat Enterprise Linux provides a full complement of network services applications, including DHCP, DNS, firewall, etc.

Red Hat Enterprise Linux 5 is based on the Linux 2.6.18 kernel and includes many enhancements over prior releases. These include:

• Per queue, switchable on-the-fly I/O schedulers
• High performance pipe implementation
• IPv4/IPv6 performance enhancements
• Support for shared cache and multi-core systems
• Kernel SMP locking enhancements for improved scalability and performance

Benefits: Improved performance and scalability across the board - memory, CPUs, I/O, networking.

Security Enhanced Linux (SELinux) provides support for MLS (Multi Level Security) policies.

Red Hat Enterprise Linux 5 services are provided with targeted policies enabled by default.

Significant ease-of-use enhancements are provided with the inclusion of the SELinux Troubleshooter, a GUI-based analyzer which guides system administrators on appropriate actions to take in the event of a security alert.

The distribution is built using the fortify-source compiler flag which provides more stringent run-time buffer bounds checking, thereby adding to overall system security.

Benefits: Red Hat Enterprise Linux offers the highest level of out-of-the-box security in the industry. Security administration is greatly simplified.

Tracks activities and modifications to the entire system, including file system operations, process system calls, user actions such as password changes, account additions/deletions/modification, use of authentication services, and configuration changes (such as time changes). Provides powerful searching and reporting tools and a unique real-time interface that permits applications to analyze and react to events as they occur.

Benefits: Auditing allows Red Hat Enterprise Linux 5 to meet US Government certifications such as CAPP/LSPP and NISPOM and also assist organizations to meet regulatory requirements such as Sarbanes, Oxley, and HIPPA.

To simplify system growth and virtualisation adoption, Red Hat Enterprise Linux 5 includes single system/guest versions of three distributed system technologies:

• Logical Volume Manager (LVM): for creating and managing pools of virtual storage devices
• Global File System (GFS): a high performance, scalable, POSIX compliant file system. GFS provides support for file systems with up to 8EB theoretical capacity.
• Distributed Lock Manager (DLM): a sophisticated application synchronization interface.

Single systems or virtualised guests using these technologies can be easily upgraded to operate in multi-system and multi-guest configurations by upgrading to Red Hat Enterprise Linux Advanced Platform, which provides multi-system and multi-guest (cluster-wide) versions of the LVM, GFS and DLM. This seamless migration eliminates the need to remap the storage subsystem, reformat disk partitions, or rewrite application synchronization routines when moving from a standalone server to a multi-system or virtualised configuration.

Benefits: Upgrade from small and non-virtualised systems to larger configurations while maintaining a consistent file system and logical volume configuration.

A large number of new capabilities are provided, including:

• The Ext3 file system will now support 16TB file systems.
• iSCSI and Fibre Channel can be configured during installation.
• OpenAIS - a standard API that can mask many types of faults in applications, middleware, operating systems and hardware by providing a simple framework for allowing developers to create redundant applications.
• Dm-crypt provides block-level storage device encryption.

Benefits: Enhanced storage scalability and security combined with simplified configuration.

New AutoFS and NFSv4 capabilities for UNIX interoperability include:

• Direct Map Support: providing compatibility with UNIX environments.
• Lazy-mount and unmount: greatly reduces the number of simultaneous mounts on client systems, thereby allowing efficient deployment in large NFS infrastructures.
• Maps can be shared with Sun Solaris, HP/UX, IBM AIX, and other UNIX systems.
• Authenticated binds with LDAP servers using Kerberos, Digest-MD5, etc.
• Significant NFSv4 enhancements in performance, stability and, with SecureNFS, security, and server-side delegation.

Benefits: Secure and high performance interoperability with UNIX environments.

Samba provides interoperability with Microsoft Windows file and print (CIFS) systems. New features include improved integration with Microsoft Active Directory ® with, for example, more consistent user and group mapping, and better support for nested groups. Extensive development work and numerous enhancements have improved the quality and stability of the entire subsystem.

Benefits: Robust and highly compatible integration with Microsoft Windows file/print and authentication environments.

Red Hat Enterprise Linux 5 provides the GCC 4.1 and Glibc 2.4 toolchain. SystemTap and Frysk kernel mode and user mode profiling and debugging tools simplify application development.

Benefits: Enhanced compiler and tools improves application performance and streamlines application development.

Red Hat Enterprise Linux 5 includes compatibility libraries that enable applications built on the versions 3 and 4 to run without recompilation.

Benefits: User mode applications do not need rebuilding.

Red Hat Network up2date has been replaced with the industry standard Yum updater and Pup graphical interface. A Yum plug-in provides access to Red Hat Network content channels.
Benefits:
Improved, industry standard software installer and updater. Ability to directly access public software repositories.

Each version of Red Hat Enterprise Linux has a defined 7-year lifecycle for errata and support. See http://www.redhat.com/security/updates/errata/ for a detailed overview of the lifecycle for each version of Enterprise Linux.
Benefits:
7-year lifecycle of errata and support.

Red Hat Enterprise Linux Advanced Platform provides dramatic capabilities beyond basic Enterprise Linux 5. Integrated server and storage virtualisation technologies. In a single, easily managed product. With a complete and highly functional environment.

With virtualisation that has the capabilities an IT organization needs:

• easy to deploy
• simple to manage
• flexible
• available

Note: Existing Red Hat Enterprise Linux AS customers will be automatically entitled to receive Advanced Platform when they renew their subscription. Early renewals are available on request.

Critical technologies in a single solution. Fully integrated. Ready to go. No need to purchase additional products from multiple vendors.

• Unlimited virtualised guests: Multiple operating systems, multiple versions, multiple performance and security settings, all running on the same server using Red Hat's virtualisation technology.
• Storage virtualisation: Multiple guests, running on the same or different servers, access and share logical storage volumes and file systems. Reap the full benefits of server virtualisation with shared storage.
• High availability clustering and failover: Application and guest operating system failover.
• Management: Includes comprehensive management capabilities.

Red Hat Enterprise Linux Advanced Platform provides a complete, integrated virtualisation solution by including the Red Hat clustering support.

• For enhanced availability, failover at either the application or virtual machine level is provided by Cluster Suite.
• Global File System and Cluster Logical Volume Manager technology allows application data to be securely accessed and shared by any guest from any system.

GFS and Cluster Suite: Please note that with the release of Red Hat Enterprise Linux 5 Advanced Platform, Red Hat Cluster Suite and Global File System are now included in the subscription offering. Red Hat Cluster Suite and Global File System are still available as layered offerings for Red Hat Enterprise Linux versions 3 and 4.

Designed for the mainstream market, Red Hat Enterprise Linux Advanced Platform provides the industry's most complete and effective virtualised environment.

Advanced Platform eliminates the need for third party high availability, cluster file system, and logical volume management products, providing a single integrated solution.

Feature	Red Hat Enterprise Linux and Advanced Platform
Supported para-virtualised guests	Red Hat Enterprise Linux 5, Red Hat Enterprise Linux 4 Update 5 (x86 and x86-64 only)*
Supported fully-virtualised guests	Red Hat Enterprise Linux 5, Red Hat Enterprise Linux 4, Red Hat Enterprise Linux 3
Hardware and application certification	All Red Hat Enterprise Linux OEM and ISV partner certifications are valid for virtualised and non-virtualised environments except where noted
Para-virtualised guest processor hardware requirements	x86 with PAE, x86-64, Itanium2 (Red Hat Enterprise Linux 5 Update 1 only)
Fully-virtualised guest processor hardware requirements	Intel Virtualisation Technology or AMD-V
Virtualised guest memory requirements	Each active guest requires the same physical memory that it would require in a non-virtualised environment. The minimum recommended physical memory per active guest is 512MB.
Architecture support for virtualisation	Supported at product release: x86, x86-64, Itanium2 is fully supported on Red Hat Enterprise Linux 5 Update 1

_{*RHEL4 Update5 32bit para-virt guests and RHEL5 32bit para-virt guests on RHEL5 x86_64 architecture is a technology preview and it is not supported.}

Feature	Red Hat Enterprise Linux Advanced Platform	Red Hat Enterprise Linux server
Number of supported guest operating systems	Unlimited	4
Manageability	Red Hat Network, virt-manager - GUI, libvirt/virsh - scriptable library and shell, Conga cluster/storage GUI	Red Hat Network, virt-manager - GUI, libvirt/virsh - scriptable library and shell
Cluster Suite failover	Yes	No
Distributed Lock Management	Operates fully distributed across multiple virtualised guests and physical systems	Operates within a single virtualised guest or physical system
Global File System	Operates fully distributed across multiple virtualised guests and physical systems	Operates within a single virtualised guest or physical system
Logical Volume Management	Operates fully distributed across multiple virtualised guests and physical systems	Operates within a single virtualised guest or physical system
Maximum supported server size	Unlimited	Up to 2 CPU sockets

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