Persistent is currently the more commonly used database. When the database is found to be down when writing a dynamic web page, the database can be restarted in this way, and the data still exists. A Persistent Volume (PV) is a cluster storage system that has been provided by the administrator or dynamically supplied by the Storage Classes. It's a cluster resource much as a cluster resource is a node. PVs are volume modules like Volumes, but also have a lifecycle independently of any particular Pod which uses PV. This API object collects the specifics of the storage architecture. Before continue download the file for this pages section tutorial,


Now you need to install the nfs-server at VM1, VM2, VM3, follow the command below,

  • sudo apt-get install nfs-kernel-server nfs-common

  • At VM1 set the shared directory, for example /var/nfsshare/ ,

    • sudo mkdir -p /var/nfsshare

      sudo chmod -R 777 /var/nfsshare/

    • Open /etc/exports and add the text file like below

      • /var/nfsshare,sync,no_root_squash,no_all_squash)

      • Local end VM1 there will be a directory /var/nfsshare/ , and also VM2, VM3 can be mounted through this path. Now, you can restart service, follow the command below,

        • systemctl restart rpcbind

          systemctl restart nfs-server

          systemctl status rpcbind

          systemctl status nfs-server

        • Next step, create a storage path for the client (VM2 , VM3)

          • sudo mkdir -p /mnt/nfs/var/nfsshare

          • Here is the command for mount and umount (uninstall) on VM1,

            • mount -t nfs /mnt/nfs/var/nfsshare

              umount /mnt/nfs/var/nfsshare

            • After mounting, cd switch to the cd /mnt/nfs/var/nfsshare path and use touch to test,

              • touch a b c d

              • You can see the result on your client VM2, VM3 because the server VM1 has been synchronized, and you can see ls of the result touch command on the at the Client and Server,

                Kubernetes Network Storage

                Provide network storage (persistent) in kubernetes, Now you can edit 1.yaml to create a my-pv service with 5G storage space , 2.yaml is asking for 1G of space from my-pv. If obtained successfully, a my-pvc service will be generated and 3.yaml to change my-pvc to task-pv-pod and bind it to the httpd default path

                • gedit 1.yaml &

                  gedit 2.yaml &

                  gedit 3.yaml &

                  gedit pv.yaml &

                  gedit pvc.yaml &

                • After editing, you can start the yaml file,

                  • kubectl apply -f 1.yaml

                    kubectl get pv

                    kubectl apply -f 2.yaml

                    kubectl get pvc

                    kubectl apply -f 3.yaml

                    kubectl get pods

                  • The command above, when start to run 1.yaml means the pv service is established, after that, continue to run 2.yaml means you can see that my-pv and my-pvc have been bound and then together and last, when you run 3.yaml you cann check the pod information. Now, you can see task-pv-pod detailed, by run command,

                    • kubectl get pods -o wide

                    • And you can try to carry out testing using command curl IP/filename.html


                      ConfigMaps allow you to decouple configuration artifacts from image content to keep containerized applications portable. This section provides a series of usage examples demonstrating how to create ConfigMaps. The first step is to create a yaml file and start the configmap service, create an archive configmap.yaml, and start the service, by following command,

                      • kubectl apply -f configmap.yaml

                        kubectl get configmap

                        kubectl get cm

                        kubectl describe cm cm-demo

                      • After that, you can use file to generate configmap service, Create a folder testcm, and create two files mysql.confas and redis.conf , the contents are as follows After create the file, follow the command below,

                        • kubectl create configmap cm-demo1 --from-file=testcm

                        • The third step is to generate directly with command,

                          • kubectl create configmap cm-demo3 --from-literal=db.host=localhost --from-literal=db.port=3306

                          • To use the configmap you can create testpod.yaml and start service, it can be initialized the environment variables of the pod and set the system environment, so run the following command below,

                            • kubectl apply -f testpod.yaml

                              kubectl logs testcm1-pod