Add the PV and PVC requirements for the domain home on PV usage documentation.

Author: ankedia

documentation/site/content/managing-domains/domain-on-pv/usage.md

@@ -142,7 +142,14 @@ for you.
 The specifications of `PersistentVolume` and `PersistentVolumeClaim` are environment specific and often require information
 from your Kubernetes cluster administrator. See [Persistent Storage](#references) in different environments.
 
-For example, if you specify the specification of the `Persistent Volume` and `Persistent Volume Claim` in the domain resource YAML file,  
+##### PV and PVC requirements
+- Domain on PV requires that the PV and PVC are created with `Filesystem` volume mode; `Block` volume mode is **not** supported.
+  - If you request that the operator creates the PV and PVC, then it uses the default `Filesystem` volume mode.
+  - If you plan to use an existing PV and PVC, then ensure that it was created with `Filesystem` volume mode.
+- You must use a storage provider that supports the `ReadWriteMany` option.
+- The operator will automatically set the owner of all files in the domain home on the persistent volume to `uid 1000` with `gid 0`. If you want to use a different user and group, then configure the desired `runAsUser` and `runAsGroup` in the security context under the `spec.serverPod.podSecurityContext` section of the Domain YAML file. The operator will use these values when setting the owner for files in the domain home directory.
+
+For example, if you provide the specification of the `Persistent Volume` and `Persistent Volume Claim` in the domain resource YAML file,  
 then the operator will create the `PV` and `PVC`, and mount the persistent volume to the `/share` directory.
 
 ```

documentation/site/content/samples/domains/domain-home-on-pv/sample.md

@@ -1,15 +1,21 @@
 ---
-title: "Domain on PV sample"
+title: "Sample"
 date: 2019-02-23T17:32:31-05:00
 weight: 3
 description: "Sample for creating a WebLogic domain home on a PV for deploying the generated WebLogic domain."
 ---
 
 {{< table_of_contents >}}
 
+{{% notice note %}}
+
+**Before you begin**: Perform the steps in [Prerequisites]({{< relref "/samples/domains/domain-home-on-pv/prerequisites.md" >}}) and then build a Domain on PV `domain creation image` by completing the steps in [Build the domain creation image]({{< relref "/samples/domains/domain-home-on-pv/build-domain-creation-image#build-the-domain-creation-image" >}}).
+If you are taking the `JRF` path through the sample, then substitute `JRF` for `WLS` in your image names and directory paths. Also note that the JRF-v1 model YAML file differs from the WLS-v1 YAML file (it contains an additional `domainInfo -> RCUDbInfo` stanza).
+{{% /notice %}}
+
 ### Overview
 
-The sample demonstrates setting up a WebLogic domain with a domain home on a Kubernetes PersistentVolume (PV) (Domain on PV). This involves:
+The sample demonstrates setting up a WebLogic domain with a domain home on a Kubernetes PersistentVolume (PV) (**Domain on PV**). This involves:
 
   - Using the [domain creation image](#domain-creation-image) that you previously built.
   - Creating secrets for the domain.
@@ -19,11 +25,6 @@ The sample demonstrates setting up a WebLogic domain with a domain home on a Kub
     - Defines PV and PVC metadata and specifications in the `spec.configuration.initializeDomainOnPV` section to create a PV and PVC (optional).
 
 
-{{% notice note %}}
-**Before you begin**: Perform the steps in [Prerequisites]({{< relref "/samples/domains/domain-home-on-pv/prerequisites.md" >}}) and then build a Domain on PV `domain creation image` by completing the steps in [Build the domain creation image]({{< relref "/samples/domains/domain-home-on-pv/build-domain-creation-image#build-the-domain-creation-image" >}}).
-If you are taking the `JRF` path through the sample, then substitute `JRF` for `WLS` in your image names and directory paths. Also note that the JRF-v1 model YAML file differs from the WLS-v1 YAML file (it contains an additional `domainInfo -> RCUDbInfo` stanza).
-{{% /notice %}}
-
 
 **PV and PVC Notes:**
 - The specifications of PersistentVolume and PersistentVolumeClaim defined in the `spec.configuration.initializeDomainOnPV` section of the Domain resource YAML file are environment specific and often require information from your Kubernetes cluster administrator to provide the information. See [Persistent volume and Persistent Volume Claim]({{< relref "/managing-domains/domain-on-pv/usage#persistent-volume-and-persistent-volume-claim" >}}) in the user documentation for more details.