GITBOOK-1062: Pramod's Sep 4 changes

SUMMARY.md

@@ -441,7 +441,8 @@
       * [No Space Left on the Device Warning](deployment/deployment-guide/troubleshooting/no-space-left-on-the-device-warning.md)
     * [Restart Deployment or StatefulSets to Redistribute Pods across Nodes](deployment/deployment-guide/redistribute-pods-across-nodes-by-restarting-deployment-statefulsets.md)
     * [Rerun Jobs in Kubernetes Cluster](deployment/deployment-guide/rerun-jobs-in-kubernetes-cluster.md)
-  * [Persistent Storage](deployment/persistent-storage.md)
+  * [Persistent Storage](deployment/persistent-storage/README.md)
+    * [Resizing Persistent Volume Claim in Kubernetes Cluster](deployment/persistent-storage/resizing-persistent-volume-claim-in-kubernetes-cluster.md)
 * [Documentation Guides](documentation-guides/README.md)
   * [Documentation Guidelines](documentation-guides/documentation-guidelines/README.md)
     * [Embed a Miro diagram](documentation-guides/documentation-guidelines/embed-a-miro-diagram.md)

deployment/persistent-storage/resizing-persistent-volume-claim-in-kubernetes-cluster.md

@@ -0,0 +1,94 @@
+---
+description: Guide on Resizing PVC (Persistent Volume Claim) in Kubernetes Cluster
+layout:
+  title:
+    visible: true
+  description:
+    visible: false
+  tableOfContents:
+    visible: true
+  outline:
+    visible: true
+  pagination:
+    visible: true
+---
+
+# Resizing Persistent Volume Claim in Kubernetes Cluster
+
+When you require additional storage for your application, you may need to resize a Persistent Volume Claim (PVC) in the Kubernetes cluster. This document provides step-by-step instructions to resize a PVC in a Kubernetes cluster.
+
+## **Prerequisites**
+
+* Your PVC's StorageClass has to support volume expansion. Verify that your StorgeClass has `allowVolumeExpansion: true` 
+* Ensure you have the necessary permissions to edit PVCs and resize volumes.
+
+## Resizing a PVC
+
+There may be downtime when resizing a PVC in Kubernetes, especially when transferring data or resizing file systems. To securely resize a PVC, turn off the related service and follow the instructions below. 
+
+1.  Identify the PVC you want to resize. Run the below command.
+
+    ```bash
+    kubectl get pvc -n <namespace>
+    ```
+2.  Identify the pods that are using this PVC.
+
+    ```bash
+    kubectl get pods -n <namespace> --field-selector=spec.volumes.persistentVolumeClaim.claimName=<pvc-name>
+    ```
+
+    You must end the running application in order to safely resize the PVC. If the PVC is attached to a Deployment, StatefulSet, or another workload, scale it down to zero replicas.\
+    **For a Deployment**
+
+    ```bash
+    kubectl scale deployment <deployment_name> --replicas=0 -n <namespace>
+    ```
+
+    **For a StatefulSet**
+
+    ```bash
+    kubectl scale statefulset <statefulset_name> --replicas=0 -n <namespace>
+    ```
+3.  Confirm that the pods have been scaled down.
+
+    ```bash
+    kubectl get pods -n <namespace>
+    ```
+4.  Edit the PVC to update the `spec.resources.requests.storage` field with the new size. Run the following command.
+
+    ```bash
+    kubectl edit pvc <pvc-name> -n <namespace>
+    ```
+5.  Edit the storage field to Increase the storage size. For example, change 10GB to 20GB.
+
+    ```yaml
+    resources:
+      requests:
+        storage: 10Gi
+    ```
+6.  After updating the PVC, check the status to ensure the resize operation succeeds.
+
+    ```shell
+    kubectl get pvc <pvc-name> -n <namespace>
+    ```
+7.  After resizing the PVC and verifying that everything is in order, scale the deployment or stateful set back to its initial number of replicas.\
+    **For a Deployment**
+
+    ```
+    kubectl scale deployment <deployment-name> --replicas=<desired-count> -n <namespace>
+    ```
+
+    **For a StatefulSet**
+
+    ```
+    kubectl scale statefulset <statefulset-name> --replicas=<desired-count> -n <namespace>
+    ```
+8.  Verify that the pods are running
+
+    ```
+    kubectl get pods -n <namespace>
+    ```
+
+Note:
+
+You can use the Rancher UI to resize the PVC by following the procedures listed above.