Merge pull request #27339 from sftim/20210331_fix_volume_health_monitorig

Fix volume health monitoring page

Author: k8s-ci-robot

content/en/docs/concepts/storage/volume-health-monitoring.md

@@ -4,29 +4,32 @@ reviewers:
 - saad-ali
 - msau42
 - xing-yang
---
-title: Volume Health Monitoring 
+title: Volume Health Monitoring
 content_type: concept
 ---
 
 <!-- overview -->
 
-{{< glossary_tooltip text="CSI" term_id="csi" >}} volume health monitoring allows CSI Drivers to detect abnormal volume conditions from the underlying storage systems and report them as events on {{< glossary_tooltip text="PVCs" term_id="persistent-volume-claim" >}} or {{< glossary_tooltip text="Pods" term_id="pod" >}}.
-
 {{< feature-state for_k8s_version="v1.21" state="alpha" >}}
 
+{{< glossary_tooltip text="CSI" term_id="csi" >}} volume health monitoring allows CSI Drivers to detect abnormal volume conditions from the underlying storage systems and report them as events on {{< glossary_tooltip text="PVCs" term_id="persistent-volume-claim" >}} or {{< glossary_tooltip text="Pods" term_id="pod" >}}.
+
 <!-- body -->
 
-## Volume Health Monitoring
+## Volume health monitoring
+
+Kubernetes _volume health monitoring_ is part of how Kubernetes implements the Container Storage Interface (CSI). Volume health monitoring feature is implemented in two components: an External Health Monitor controller, and the {{< glossary_tooltip term_id="kubelet" text="kubelet" >}}.
 
-The Volume Health Monitoring feature is part of Kubernetes implementation of Container Storage Interface (CSI). The Volume Health Monitoring feature is implemented in two components: External Health Monitor Controller and Kubelet.
+If a CSI Driver supports Volume Health Monitoring feature from the controller side, an event will be reported on the related {{< glossary_tooltip text="PersistentVolumeClaim" term_id="persistent-volume-claim" >}} (PVC) when an abnormal volume condition is detected on a CSI volume.
 
-If a CSI Driver supports Volume Health Monitoring feature from the controller side, an event will be reported on the PVC when an abnormal volume condition is detected on a CSI volume.
+The External Health Monitor {{< glossary_tooltip text="controller" term_id="controller" >}} also watches for node failure events. You can enable node failure monitoring by setting the `enable-node-watcher` flag to true. When the external health monitor detects a node failure event, the controller reports an Event will be reported on the PVC to indicate that pods using this PVC are on a failed node.
 
-External Health Monitor Controller will also watch for node failure events. This can be enabled by setting the `enable-node-watcher` flag to true. When a node failure event is detected, an event will be reported on the PVC to indicate that pods using this PVC are on a failed node.
+If a CSI Driver supports Volume Health Monitoring feature from the node side, an Event will be reported on every Pod using the PVC when an abnormal volume condition is detected on a CSI volume.
 
-If a CSI Driver supports Volume Health Monitoring feature from the node side, an event will be reported on every Pod using the PVC when an abnormal volume condition is detected on a CSI volume.
+{{< note >}}
+You need to enable the `CSIVolumeHealth` [feature gate](/docs/reference/command-line-tools-reference/feature-gates/) to use this feature from the node side.
+{{< /note >}}
 
-Note that you need to enable the `CSIVolumeHealth` feature gate to use this feature from the node side.
+## {{% heading "whatsnext" %}}
 
-See CSI driver [docs](https://kubernetes-csi.github.io/docs/drivers.html) to find out which CSI drivers have implemented this feature.
+See the [CSI driver documentation](https://kubernetes-csi.github.io/docs/drivers.html) to find out which CSI drivers have implemented this feature.