This is one of two Red Hat Enterprise Linux-related blogs released today. It highlights something that we are proud of and applies to all Red Hat Enterprise Linux releases, our software maintenance and lifecycle policies. The other blog covers the new capabilities provided by Red Hat Enterprise Linux 5.2.

We have done a lot of work to make sure that minor releases, such as 5.2, deliver subscription value to customers. We try to strike a balance between adding improvements, which enhance customers’ ability to get more value from their IT assets, but not adding so much that it causes them to have to recertify their entire software stack. And we make it easy for customers to apply these updates by using Red Hat Network.

The Lifecycle of Enterprise Linux

The lifecycle for a major version of Red Hat Enterprise Linux is seven years. We have designed it in an effort to deliver a reliable application platform at all times. We do this by splitting our lifecycle into three phases (Full Support, Transition, Maintenance). Here’s a general outline on what we plan for during each phase:

1. Full Support
   • New hardware support
   • Enhanced software functionality (selected)
   • Bug fixes (medium, high, or urgent priority levels)
   • Security patches (important or critical impact levels)
2. Transition
   • New hardware support (very limited)
   • Bug fixes (high or urgent priority levels)
   • Security patches (important or critical impact levels)
3. Maintenance
   • Bug fixes (only those few deemed mission critical)
   • Security patches (important or critical impact levels)

In each phase of the lifecycle, software updates to Red Hat Enterprise Linux are delivered one of two ways, via a minor release (such as 5.2) or by an asynchronously released errata.

Minor releases usually contain security fixes, bug fixes, and thoroughly qualified enhancements. Generally, enhancements are limited to those necessary to enable additional hardware support as we identify those requirements. However we also add general software enhancements if and when we identify other opportunities –these enhancements are thoroughly tested to ensure that they will not cause any disruptions.

Also, we issue critical security patches and other really important updates (via errata) independently, or asynchronously, of a minor release.

One important point to note is that for the whole seven year lifecycle, Red Hat maintains binary compatibility for the core runtime across all minor and asynchronous errata releases. We also keep stable the kernel interfaces for driver modules. And, every version of Red Hat Enterprise Linux contains backwards compatibility libraries for the two previous major versions. We do this in an effort to ensure that customers can run their complete application stacks without fear of any disruption at any point during the entire seven year lifecycle.