34.2. Setting up software updates

Red Hat describes the products and packages on a Red Hat Enterprise Linux system as software content. Associate your system with a content server to update existing content or to install new content. Red Hat Enterprise Linux 6 can use Certificate-based Red Hat Network, RHN Classic, or a local content server such as Satellite or System Engine to obtain content.

These content delivery options — Red Hat Network, Red Hat Network Classic, and Satellite — are mutually exclusive. Each connects with different content and subscription services at Red Hat, and each has its own set of management tools.

34.2.1. Content delivery and subscriptions

A system can only download or receive updates for content that it is allowed, or entitled, to access. An organization buys a subscription, which is a contract that allows them to use a defined list of products in a defined amount, such as buying a subscription to Red Hat Enterprise Linux for Physical Servers (the product) which is good for 100 servers (the quantity). When it runs firstboot, the system can be associated with the organization's subscriptions so that the product subscriptions can be allocated to that machine. When a system is associated with the subscription, it is also associated with the content server which delivers the subscribed content.

34.2.1.1. Subscription and content configuration paths

The content delivery server and the subscription assignments are made in the Set Up Software Updates screens. There are four choices:

Certificate-based Red Hat Network, which focuses on product-driven subscriptions and content delivery
RHN Classic, which uses channel-driven access to content (this is provided as a migration path for older Red Hat Enterprise Linux systems)
Satellite or Proxy content delivery, which uses a channel-based system similar to RHN Classic
Register later

The firstboot process begins and ends with the same series of steps regardless of which of the three content delivery mechanisms you choose.

Figure 34.3. Subscription and content Firstboot paths

Red Hat Enterprise Linux has two conceptual steps that define how the machine will access packages and content:

It must be registered, which identifies the machine to the Red Hat Subscription Service in Certificate-based Red Hat Network and adds it to the organization's software inventory for subscription management.
It must be subscribed to an available subscription, which means that the system has the right to install in any available packages and configure a path for receiving updates.

These concepts are described in more detail in the Red Hat Enterprise Linux 6 Deployment Guide.

The Satellite and proxy configuration paths are different from Red Hat Network-based configurations and are unique to the environment. Because every installation is different, local Satellites go through guided manual configuration.

34.2.1.1.1. Choosing between Red Hat Network and RHN Classic

Beginning with Red Hat Enterprise Linux 6.1, subscriptions are defined by available and installed products. However, in older versions of Red Hat Enterprise Linux, subscriptions were defined by channel access. These are two different and mutually exclusive approaches to content and subscription access.

Certificate-based Red Hat Network is integrated closely with the Customer Portal and performs two important management tasks: subscription management and content delivery and updates. This option registers a system with the Red Hat Subscription Service and provides a robust set of tools for both locally and globally assigning subscriptions, verifying software subscription status, and viewing installed products.

Red Hat Network Classic uses the traditional channel subscription model. Red Hat Network Classic is provided for legacy support for environments with Red Hat Enterprise Linux 4, Red Hat Enterprise Linux 5.6 and earlier, Red Hat Enterprise Linux 6.0, and Satellite systems. We do not recommend Red Hat Network Classic for systems that run Red Hat Enterprise Linux 6.1 and later.

A system cannot be managed both by Certificate-based Red Hat Network (and the Subscription Manager tools) and RHN Classic (and the rhn_* tools). If a system was previously managed by RHN Classic, there is no direct, supported migration path from RHN Classic to Certificate-based Red Hat Network. If you upgrade to Red Hat Enterprise Linux 6.1 or later and want to use the new Certificate-based Red Hat Network, either:

Update the system using a boot ISO rather than yum.
Manually remove the system from RHN Classic and delete the host record, then register the system to Certificate-based Red Hat Network using the Red Hat Subscription Manager tools.