Thursday, June 16, 2011

Red Hat Enterprise Linux Support Life Cycle


Red Hat Enterprise Linux Life Cycle

Overview

Red Hat provides support and maintenance during the stated time periods for each of the major releases of Red Hat Enterprise Linux (RHEL), the "Life Cycle".
The Life Cycle allows customers and partners to effectively plan, deploy and support Red Hat Enterprise Linux. Each major release of RHEL is denoted by a single number, i.e.: RHEL 4, RHEL 5, RHEL 6.
The RHEL Life Cycle identifies the various levels of maintenance for each major release of RHEL over a total period of up to ten years from the initial release date, which is often referred to as the general availability (GA) date. The RHEL Life Cycle is designed to reduce the level of change within each major release over time, increasing predictability and decreasing maintenance costs. Red Hat published this Life Cycle in an effort to provide as much transparency as possible and may make exceptions from these policies as conflicts may arise.
Software changes to RHEL are delivered via individual updates known as "Errata Advisories", generally through Red Hat Network (RHN) or other authorized portals. Errata Advisories can be released individually on an as-needed basis or aggregated as a Service Pack (or "SP", also referred to as a "Minor Release" or "Update"). Errata Advisories may contain security, bug fixes or feature enhancements. Red Hat may release any Errata Advisories independent of customer reported issues and will generally do so for critical impact security issues. All Errata Advisories are tested and qualified against the appropriate Red Hat Enterprise Linux release(s). All released Errata Advisories will remain accessible to active subscribers for the entire Life Cycle.
Every major release of Red Hat Enterprise Linux is maintained and supported independently during the 10 year Life Cycle. Within each major release of Red Hat Enterprise Linux, any Errata Advisory (including when released as part of a Service Pack) will only be applied incrementally to the previously released Errata Advisories.
During the entire Life Cycle, Red Hat makes commercially reasonable efforts to maintain binary compatibility for the core runtime environment across all Service Packs and asynchronous errata advisories. Red Hat may elect to make exceptions to the compatibility goal for critical impact security or other significant issues. Furthermore, major releases of Red Hat Enterprise Linux contain a limited set of backward-compatible libraries from the previous major releases to allow for the easy migration of applications. In order to minimize the amount of change and to maintain the binary compatibility, fixes generally are back-ported to the respective version of RHEL. Exceptions may apply for controlled re-bases, packages that are provided primarily to satisfy dependencies, or Desktop applications.
7-year regular life cycle3-year extended life cycle
Year 1Year 2Year 3Year 4Year 5Year 6Year 7Year 8Year 9Year 10
*This is a schematic view of the Life Cycle, time-spans and dates within the 7 year life cycle are subject to adjustment.

Details

The Life Cycle for a major version of Red Hat Enterprise Linux is up to ten years consisting of a Regular Life Cycle of seven years plus an optional extension of three years. All RHEL subscriptions include the regular seven-year life cycle. Customers wishing to deploy for an extended period can request up to an additional three years for the Life Cycle.
The Life Cycle is broadly divided into four individual phases:
Production 1(Approximately 4 years)Production 2(Approximately 1 year)Production 3(Approximately 2 years)Extended Life Cycle(Additional 3 years)
Year 1Year 2Year 3Year 4Year 5Year 6Year 7Year 8Year 9Year 10
*This is a schematic view of the Life Cycle, time-spans and dates within the 7 year life cycle are subject to adjustment.
The following table details what type of software maintenance is performed during each phase of the ten year Life Cycle:
Life-cycle phase
DescriptionProduction 1Production 2Production 3Extended Life CycleEUS
Access to previously released content in Red Hat NetworkYesYesYesYesOptional7
Self-help through documentation, Red Hat knowledge base, etc.YesYesYesYesOptional7
Unlimited Incident Technical Support1YesYesYesOptional7Optional7
Asynchronous Security ErrataYesYesYesOptional7Optional7
Asynchronous Bug Fix Errata2YesYesYesOptional7Optional7
Service PacksYesYesNoNoN/A
Refreshed Hardware Enablement3NativeLimited4NativeThrough VirtualizationThrough VirtualizationThrough Virtualization
Software enhancements5Yes6NoNoNoNo
Updated install imagesYesNo8NoNoNo
  1. Support access depends on the Service Level chosen for your RHEL Subscription. Full details of Support Services are provided as part of the Subscription Agreement.
  2. Red Hat may choose to address catastrophic issues with a significant business impact for the customer through a Hotfix as a temporary measure while the bug fix errata is being created.
  3. Native hardware enablement is provided by backporting hardware drivers, etc. Hardware enablement through virtualization is achieved by running a prior version of Enterprise Linux as a virtual guest on a newer version of Red Hat Enterprise Linux. See below for details (Virtualization).
  4. Limited to hardware that does not require substantial software changes, see text for details (Production 2).
  5. Software enhancements are additions of functionality beyond correcting defects or enabling previously existing functionality on a new hardware generation.
  6. Major releases are the primary vehicle for software enhancements.
  7. See Extended Life Cycle description below.
  8. Unless required because of install-path defects.

Production 1 Phasei:

During the Production 1 phase, at a minimum, qualified security Errata Advisories of important, critical impact and urgent priority bug-fix errata may be released as they become available.
If available, new or improved hardware support and select enhanced software functionality may be provided at the discretion of Red Hat, generally via Service Packs. Hardware support that does not require substantial software changes may be provided independent from Service Packs at the discretion of Red Hat.
Service Packs will also include available and qualified Errata Advisories. Service Packs are cumulative thus including the contents of previously released updates. The focus for Service Packs during this phase lies on resolving defects of medium or higher priority.
Updated install images will be provided for Service Packs during the Production 1 phase.

Production 2 Phaseii:

During the Production 2 phase, at a minimum, qualified security Errata Advisories of important, critical or urgent priority bug-fix errata may be released as they become available.
If available, refreshed hardware support that does not require substantial software changes may be provided at the discretion of Red Hat, generally via Service Packs. New software functionality is not available during this phase.
Service Packs will also include all available and qualified errata. Service Packs are cumulative thus including the contents of previously released updates, including those from Production 1 phase. The focus for Service Packs during this phase lies on resolving defects with a minimum priority of high.
Updated install images will only be provided for Service Packs during the Production 2 phase if required due to installer changes at Red Hat's discretion.

Production 3 Phaseiii:

During the Production 3 phase, at a minimum, qualified security Errata Advisories of critical impact, as well as, selected urgent priority bug-fix errata may be released as they become available.
No new functionality, new hardware support or updated installation images are planned for release in Production 3 phase. There are no Service Packs planned during this phase.

Extended Life Cycle Phase:

During the Extended Life Cycle Phase, active subscribers continue to receive access to previously released content on RHN as well as other content such as documentation and the Red Hat Knowledge Base through the Red Hat customer portal.
As an optional add-oniv to a regular Red Hat Enterprise Linux subscription, Red Hat offers Extended Life Cycle Support (ELS) Subscriptions.
ELS provides critical impact security fixes and selected urgent priority defect fixes that are available and qualified for a subset of the packages in a specific major releases of Red Hat Enterprise Linux beyond the end of its regular 7-year life cycle. For ELS subscribers, Red Hat will generally continue to provide the critical impact security fixes independent of customer requests.
The individual ELS streams will be maintained for an additional 3 years after the end-date of the Regular Life Cycle of the relevant release (extending the Life Cycle to 10 years). ELS is provided for a limited set of software packages on a limited number of hardware architectures.

Virtualization

Red Hat intends to support versions of Red Hat Enterprise Linux, that are still within their seven year life cycle, running as virtualized guests on later versions of Red Hat Enterprise Linux. Each version of RHEL under Extended Life Cycle Support will be supported as a guest on host versions, supported during its Regular Life Cycle of 7 years.
Hardware certification (including the associated hardware limits) is based on the version of Enterprise Linux that is being used as the host. Red Hat, at its discretion, may provide additional optimization for specific virtualization scenarios (such as para-virtualized drivers).
The Red Hat Enterprise Linux virtualization support matrix provides details on the supported combinations of operating systems, versions, and hardware architectures.

Life Cycle Dates

Red Hat Enterprise Linux 3
General AvailabilityEnd of Production 1End of Production 2End of Production 3 End of Regular Life CycleEnd of Extended Life Cycle
October 23, 2003July 20, 2006June 30, 2007October 31, 2010October 31, 2013
Red Hat Enterprise Linux 4
General AvailabilityEnd of Production 1End of Production 2End of Production 3 End of Regular Life CycleEnd of Extended Life Cycle
February 14, 2005March 31, 2009Q1 2011February 29, 2012February 28, 2015
Red Hat Enterprise Linux 5
General AvailabilityEnd of Production 1End of Production 2End of Production 3 End of Regular Life CycleEnd of Extended Life Cycle
March 15, 2007Q4 2011Q4 2012March 31, 2014March 31, 2017
Red Hat Enterprise Linux 6
General AvailabilityEnd of Production 1End of Production 2End of Production 3 End of Regular Life CycleEnd of Extended Life Cycle
November 10, 2010Q4 of 2014Q4 of 2015November 30, 2017November 30, 2020

Extended Update Support

As an optional add-on to a standard Red Hat Enterprise Linux subscription, Red Hat offers Extended Update Support (EUS) Subscriptions. EUS provides an independent Life Cycle for individual Service Packs in parallel to the otherwise single, incrementally maintained main stream. Active subscribers to EUS receive critical impact security fixes and selected urgent priority defect fixes that are available and qualified for the respective individual Service Pack of Red Hat Enterprise Linux after the release of and in parallel to subsequent Service Packs. For EUS subscribers, Red Hat generally will continue to provide the critical impact security fixes independent of customer requests.
In Red Hat Enterprise Linux 4, EUS is available for the following Service Packs (sometimes called "Minor Releases" or "Updates"):
  • 4.5 (ended 6 months after 4.7 availability)
  • 4.7 (until August 31st, 2011)
In Red Hat Enterprise Linux 5, EUS is available for the following Service Packs (sometimes called "Minor Releases" or "Updates"):
  • 5.2 (ended 6 months after 5.4 availability)
  • 5.3 (until November 30, 2010)
  • 5.4 (until 6 months after 5.6)
  • 5.6 (until 6 months after 5.8)
In Red Hat Enterprise Linux 6, EUS is available for all Service Packs released during the Production I phase (but not for the Service Pack marking transition to Production II or any Service Packs released during the Production II phase). Each EUS stream will be available for a length of 24 months from the release of the respective Service Pack.
  • i. The Production 1 phase was formerly called the "Full Support" phase.
  • ii. The Production 2 phase was formerly called the "Deployment" or "Transition" phase.
  • iii. The Production 3 phase was formerly called the "Maintenance" phase.
  • iv. For details on the ELS add-on subscriptions please refer to http://www.redhat.com/rhel/server/extended_lifecycle_support/