Recommend users run `precheck` before upgrading (#9612)

content/en/docs/setup/upgrade/canary/index.md

@@ -17,6 +17,16 @@ at the same time. A canary version of an upgrade can be started by installing th
 next to the old one, using a different `revision` setting. Each revision is a full Istio control plane implementation
 with its own `Deployment`, `Service`, etc.
 
+## Before you upgrade
+
+Before upgrading Istio, it is recommended to run the `istioctl x precheck` command to make sure the upgrade is compatible with your environment.
+
+{{< text bash >}}
+$ istioctl x precheck
+✔ No issues found when checking the cluster. Istio is safe to install or upgrade!
+  To get started, check out https://istio.io/latest/docs/setup/getting-started/
+{{< /text >}}
+
 ## Control plane
 
 To install a new revision called `canary`, you would set the `revision` field as follows:

content/en/docs/setup/upgrade/helm/index.md

@@ -26,6 +26,14 @@ follow the instructions below.
 
 {{< boilerplate helm-jwt-warning >}}
 
+Before upgrading Istio, it is recommended to run the `istioctl x precheck` command to make sure the upgrade is compatible with your environment.
+
+{{< text bash >}}
+$ istioctl x precheck
+✔ No issues found when checking the cluster. Istio is safe to install or upgrade!
+To get started, check out https://istio.io/latest/docs/setup/getting-started/
+{{< /text >}}
+
 ### Create a backup
 
 {{< boilerplate helm-backup >}}

content/en/docs/setup/upgrade/in-place/index.md

@@ -52,6 +52,14 @@ can be found in the `bin/` subdirectory of the downloaded package.
     $ kubectl config view
     {{< /text >}}
 
+1. Ensure that the upgrade is compatible with your environment.
+
+    {{< text bash >}}
+    $ istioctl x precheck
+    ✔ No issues found when checking the cluster. Istio is safe to install or upgrade!
+    To get started, check out https://istio.io/latest/docs/setup/getting-started/
+    {{< /text >}}
+
 1. Begin the upgrade by running this command:
 
     {{< text bash >}}