DOC-573: add mount PVC topic (#330)

For https://hazelcast.atlassian.net/browse/DOC-573

As part of the Diagnostic Logging work, we need to document how to mount
one or more Persistent Volume Claims (PVCs) directly to a Hazelcast
cluster.

Sergii suggests this goes into a new topic under Configuration
properties.

The work to add the fields to the CRD has been done in PR:
hazelcast/hazelcast-platform-operator#1432

Author: amandalindsay

docs/modules/ROOT/nav.adoc

@@ -80,6 +80,7 @@
 ** xref:hazelcast-parameters.adoc[System properties]
 ** xref:custom-config.adoc[Custom configuration]
 ** xref:jvm-parameters.adoc[JVM parameters]
+** xref:mount-pvc.adoc[Mount PVC on a cluster]
 
 * Management Center
 ** xref:management-center-clusters.adoc[Hazelcast clusters]

docs/modules/ROOT/pages/mount-pvc.adoc

@@ -0,0 +1,41 @@
+= Mount Persistent Volume Claims for Hazelcast clusters
+
+You can mount one or more Persistent Volume Claims (PVCs) directly to your Hazelcast cluster. Each PVC defined in the `persistenceVolumeClaims` section will be mounted under the path `/data/<name-of-pvc>`. This approach allows you to use PVCs for any Hazelcast feature that requires persistent storage, simply by referencing the PVC by its name.
+
+== How it works
+
+- Define one or more PVCs in the `persistenceVolumeClaims` section of your Hazelcast custom resource (CR).
+- Each PVC will be mounted at `/data/<name>`, where `<name>` is the value of the name field in your PVC configuration.
+- Features that require persistent storage (such as diagnostics, persistence, or the CP Subsystem) can reference the PVC by specifying its name, using the appropriate field (e.g., `pvcName`).
+
+This mechanism decouples the PVC definition from feature configuration, making it easier to manage and reuse storage across different Hazelcast features.
+
+For more information, see the xref:api-ref.adoc#[API]. For a tutorial on enabling persistence, see link:https://docs.hazelcast.com/hazelcast/latest/getting-started/persistence[Persist Map Entries on Disk]
+
+== Example: Configure diagnostics with a named PVC
+
+Below is an example configuration that shows how to define a PVC and use it for diagnostics logging by specifying the `pvcName` field. The diagnostics logs will be stored in the PVC mounted at `/data/diagnostics-pvc-volume`.
+
+[source,yaml]
+----
+apiVersion: hazelcast.com/v1alpha1
+kind: Hazelcast
+metadata:
+ name: hazelcast
+spec:
+ clusterSize: 3
+ repository: 'docker.io/hazelcast/hazelcast-enterprise'
+ version: 5.6.0-SNAPSHOT
+ licenseKeySecretName: hazelcast-license-key
+ diagnostics:
+   outputType: STDOUT
+   maxRolledFileCount: 10
+   maxRolledFileSize: '50M'
+   pvcName: diagnostics-pvc-volume
+ persistenceVolumeClaims:
+   - accessModes: [ "ReadWriteOnce" ]
+     requestStorage: 1Gi
+     storageClassName: "standard"
+     name: diagnostics-pvc-volume
+----
+