docs(upgrade) pre-upgrade check will event

Signed-off-by: James Munson <james.munson@suse.com>

content/docs/1.6.4/deploy/important-notes/index.md

@@ -111,7 +111,7 @@ If you have Longhorn volume manifests or scripts that are still using `v1beta1`
 
 Beginning with version v1.6.0, Longhorn is implementing mandatory engine upgrades. See the [release note](https://github.com/longhorn/longhorn/releases/tag/v{{< current-version >}}) for information about the minimum supported engine image version.
 
-When upgrading through Helm, a component compatibility check is automatically performed. If the new Longhorn is not compatible with the engine images that are currently in use, the upgrade path is blocked through a pre-hook mechanism.
+When upgrading through Helm, a component compatibility check is automatically performed. If the new Longhorn is not compatible with the engine images that are currently in use, the upgrade path is blocked through a pre-hook mechanism. The upgrade will stop and the reason for the check's failure will be recorded in an event.  For more detail, see [Upgrading Longhorn Manager](../../deploy/upgrade/longhorn-manager).
 
 If you installed Longhorn using the manifests, engine upgrades are enforced by the Longhorn Manager. Attempts to upgrade Longhorn Manager may cause unsuccessful pod launches and generate corresponding error logs, although it poses no harm. If you encounter such errors, you must revert to the previous Longhorn version and then upgrade the engines that are using the incompatible engine images before the next upgrade.
 

content/docs/1.6.4/deploy/upgrade/longhorn-manager.md

@@ -116,7 +116,13 @@ Besides, users might need to delete new components introduced by the new version
 
 To prevent any impact caused by failed upgrades from unsupported versions, Longhorn will automatically initiate a new job (`pre-upgrade`) to verify if the upgrade path is supported before upgrading when upgrading through `Helm` or `Rancher App Marketplace`.
 
-The `pre-upgrade` job will block the upgrade process and provide the failure reason in the logs of the pod.
+The `pre-upgrade` job will block the upgrade process and provide the failure reason in the logs of the pod.  It will also be recorded in an event, for instance:
+
+```
+2m33s               Normal    Created                 Pod/longhorn-pre-upgrade-v5tqq    Created container longhorn-pre-upgrade
+2m33s               Warning   FailedUpgradePreCheck   /longhorn-pre-upgrade             failed to upgrade since upgrading from v1.4.3 to v1.6.4 for minor version is not supported
+```
+
 During the upgrade failure, the user's Longhorn system should remain intact without any impacts.
 
 To recover, you need to run the below commands to rollback to the previously installed revision:

content/docs/1.7.3/deploy/upgrade/longhorn-manager.md

@@ -157,7 +157,13 @@ Besides, users might need to delete new components introduced by the new version
 
 To prevent any impact caused by failed upgrades from unsupported versions, Longhorn will automatically initiate a new job (`pre-upgrade`) to verify if the upgrade path is supported before upgrading when upgrading through `Helm` or `Rancher App Marketplace`.
 
-The `pre-upgrade` job will block the upgrade process and provide the failure reason in the logs of the pod.
+The `pre-upgrade` job will block the upgrade process and provide the failure reason in the logs of the pod.  It will also be recorded in an event, for instance:
+
+```
+2m33s               Normal    Created                 Pod/longhorn-pre-upgrade-v5tqq    Created container longhorn-pre-upgrade
+2m33s               Warning   FailedUpgradePreCheck   /longhorn-pre-upgrade             failed to upgrade since upgrading from v1.5.4 to v1.7.3 for minor version is not supported
+```
+
 During the upgrade failure, the user's Longhorn system should remain intact without any impacts.
 
 To recover, you need to run the below commands to rollback to the previously installed revision:

content/docs/1.7.3/important-notes/_index.md

@@ -14,6 +14,7 @@ Please see [here](https://github.com/longhorn/longhorn/releases/tag/v{{< current
   - [Minimum XFS Filesystem Size](#minimum-xfs-filesystem-size)
   - [Longhorn PVC with Block Volume Mode](#longhorn-pvc-with-block-volume-mode)
   - [Container-Optimized OS Support](#container-optimized-os-support)
+  - [Upgrade Check Events](#upgrade-check-events)
 - [Resilience](#resilience)
   - [RWX Volumes Fast Failover](#rwx-volumes-fast-failover)
   - [Timeout Configuration for Replica Rebuilding and Snapshot Cloning](#timeout-configuration-for-replica-rebuilding-and-snapshot-cloning)
@@ -145,6 +146,9 @@ From this version, you need to add group id 6 to the security context or run con
 
 Starting with Longhorn v1.7.0, Longhorn supports Container-Optimized OS (COS), providing robust and efficient persistent storage solutions for Kubernetes clusters running on COS. For more information, see [Container-Optimized OS (COS) Support](../advanced-resources/os-distro-specific/container-optimized-os-support/).  
 
+### Upgrade Check Events
+Longhorn performs a pre-upgrade check when upgrading with Helm or Rancher App Marketplace.  If a check fails, the upgrade will stop and the reason for the check's failure will be recorded in an event.  For more detail, see [Upgrading Longhorn Manager](../deploy/upgrade/longhorn-manager).
+
 ## Resilience
 
 ### RWX Volumes Fast Failover

content/docs/1.8.0/deploy/upgrade/longhorn-manager.md

@@ -157,7 +157,13 @@ Besides, users might need to delete new components introduced by the new version
 
 To prevent any impact caused by failed upgrades from unsupported versions, Longhorn will automatically initiate a new job (`pre-upgrade`) to verify if the upgrade path is supported before upgrading when upgrading through `Helm` or `Rancher App Marketplace`.
 
-The `pre-upgrade` job will block the upgrade process and provide the failure reason in the logs of the pod.
+The `pre-upgrade` job will block the upgrade process and provide the failure reason in the logs of the pod.  It will also be recorded in an event, for instance:
+
+```
+2m33s               Normal    Created                 Pod/longhorn-pre-upgrade-v5tqq    Created container longhorn-pre-upgrade
+2m33s               Warning   FailedUpgradePreCheck   /longhorn-pre-upgrade             failed to upgrade since upgrading from v1.6.2 to v1.8.0 for minor version is not supported
+```
+
 During the upgrade failure, the user's Longhorn system should remain intact without any impacts.
 
 To recover, you need to run the below commands to rollback to the previously installed revision:

content/docs/1.8.0/important-notes/_index.md

@@ -14,6 +14,7 @@ Please see [here](https://github.com/longhorn/longhorn/releases/tag/v{{< current
   - [Minimum XFS Filesystem Size](#minimum-xfs-filesystem-size)
   - [Longhorn PVC with Block Volume Mode](#longhorn-pvc-with-block-volume-mode)
   - [Container-Optimized OS Support](#container-optimized-os-support)
+  - [Upgrade Check Events](#upgrade-check-events)
 - [Resilience](#resilience)
   - [RWX Volumes Fast Failover](#rwx-volumes-fast-failover)
   - [Timeout Configuration for Replica Rebuilding and Snapshot Cloning](#timeout-configuration-for-replica-rebuilding-and-snapshot-cloning)
@@ -147,6 +148,9 @@ From this version, you need to add group id 6 to the security context or run con
 
 Starting with Longhorn v1.7.0, Longhorn supports Container-Optimized OS (COS), providing robust and efficient persistent storage solutions for Kubernetes clusters running on COS. For more information, see [Container-Optimized OS (COS) Support](../advanced-resources/os-distro-specific/container-optimized-os-support/).  
 
+### Upgrade Check Events
+Longhorn performs a pre-upgrade check when upgrading with Helm or Rancher App Marketplace.  If a check fails, the upgrade will stop and the reason for the check's failure will be recorded in an event.  For more detail, see [Upgrading Longhorn Manager](../deploy/upgrade/longhorn-manager).
+
 ## Resilience
 
 ### RWX Volumes Fast Failover