Merge pull request #37939 from codyhoag/eus-updates

EUS channel updates

Author: codyhoag

modules/understanding-upgrade-channels.adoc

@@ -19,7 +19,7 @@ ifndef::openshift-origin[]
 * `candidate-{product-version}`
 * `fast-{product-version}`
 * `stable-{product-version}`
-* `eus-4.6` (only available when running 4.6)
+* `eus-4.y` (only when running an even-numbered 4.y cluster release, like 4.10)
 
 If you do not want the Cluster Version Operator to fetch available updates from the upgrade recommendation service, you can use the `oc adm upgrade channel` command in the OpenShift CLI to configure an empty channel. This configuration can be helpful if, for example, a cluster has restricted network access and there is no local, reachable upgrade recommendation service.
 
@@ -76,15 +76,15 @@ endif::openshift-origin[]
 
 ifndef::openshift-origin[]
 [discrete]
-== eus-4.6 channel
+== eus-4.y channel
 
-In addition to the stable channel, certain minor versions of {product-title} offer an link:https://access.redhat.com/support/policy/updates/openshift#ocp4_phases[Extended Update Support] (EUS). These EUS versions extend the maintenance phase for customers with Premium Subscriptions to 14 months. {product-title} 4.6 is currently the only minor version with EUS.
+In addition to the stable channel, all even-numbered minor versions of {product-title} offer an link:https://access.redhat.com/support/policy/updates/openshift#ocp4_phases[Extended Update Support] (EUS). These EUS versions extend the Full and Maintenance support phases for customers with Standard and Premium Subscriptions to 18 months.
 
-Although there is no difference between stable-4.6 and eus-4.6 channels until {product-title} 4.6 transitions to the EUS phase, you can switch to the EUS channel as soon as it becomes available. When {product-title} 4.6 transitions to the EUS phase of its lifecycle, the stable-4.6 channel will no longer receive subsequent z-stream updates. After you upgrade to a version that is exclusive to the EUS channel, that cluster will no longer be eligible for minor version upgrades until upgrades to the next EUS version become available. The next planned EUS version is to be 4.10 and the upgrade to that version will require a serial set of version upgrades, such as from 4.6 to 4.7 to 4.8 to 4.9 to 4.10.
+Although there is no difference between `stable-4.y` and `eus-4.y` channels until {product-title} 4.y transitions to the EUS phase, you can switch to the `eus-4.y` channel as soon as it becomes available. 
 
-Additionally, you may only switch to the EUS channel when your cluster is running a supported version of {product-title} 4.6.
+When upgrades to the next EUS channel are offered, you can switch to the next EUS channel and upgrade until you have reached the next EUS version.
 
-Finally, if you install a 4.6 version that is exclusive to EUS, you will similarly not be able to upgrade to a later minor version until upgrades are provided to 4.10.
+This upgrade process does not apply for the `eus-4.6` channel.
 endif::openshift-origin[]
 
 [discrete]