NAS volume CSI

The latest service changes have not yet been reflected in this content. We will update the content as soon as possible. Please refer to the Korean version for information on the latest updates.

Available in VPC

If files are added to a running container, then all files are deleted when the process is terminated or the container is restarted due to a failed health check of Kubernetes Liveness Probe. You can use the NAS volume for such cases and adjust the settings so that the added files will be kept, even after the process is terminated or the container is restarted.

You can create a PersistentVolumeClaim (PVC) and add it when you deploy the NAS volume container.

NAVER Cloud Platform's Ncloud Kubernetes Service provides Container Storage Interface (CSI) as a volume driver. This driver is connected with Kubernetes and supports tasks such as NAS volume creation, deletion, resizing, etc.

Supported versions and capacity

It describes supported versions and capacity information.

Supported versions

NAVER Cloud Platform supports the following versions of NAS CSI and Kubernetes compatible with it.

This Kubernetes version supports the following storage services:

Assignable capacity

You can assign capacity in the units of 100 GB to Kubernetes NAS volume through CSI. If the volume size is not defined separately, then a NAS volume of 500 GB will be created by default. The minimum and maximum capacity assignable is as follows:

• Minimum: 500 GB
• Maximum: 10,000 GB

NAS CSI driver installation (for existing clusters not installed yet)

NAS CSI driver is deployed when installing Kubernetes. This clause describes how to install NAS CSI in the existing cluster not installed yet. If the NAS CSI is already installed, you don’t need to do the following action.

Deploy NAS CSI Deploy

The following files indicates the latest stable version. If a problem occurs during the installation, run the kubectl apply -f command again to reflect the missing resources.

• Korea Region

# kubernetes version >= 1.22
$ kubectl --kubeconfig=$KUBE_CONFIG apply -f https://kr.object.ncloudstorage.com/nks-download/nas-csi/pub/kr/v2.0.1/nas-csi.yaml

# kubernetes version < 1.22
$ kubectl --kubeconfig=$KUBE_CONFIG apply -f https://kr.object.ncloudstorage.com/nks-download/nas-csi/pub/kr/v1.0.2/nas-csi.yaml

• Singapore region

# kubernetes version >= 1.22
$ kubectl --kubeconfig=$KUBE_CONFIG apply -f https://kr.object.ncloudstorage.com/nks-download/nas-csi/pub/sgn/v2.0.1/nas-csi.yaml

# kubernetes version < 1.22
$ kubectl --kubeconfig=$KUBE_CONFIG apply -f https://kr.object.ncloudstorage.com/nks-download/nas-csi/pub/sgn/v1.0.2/nas-csi.yaml

• Japan region

# kubernetes version >= 1.22
$ kubectl --kubeconfig=$KUBE_CONFIG apply -f https://kr.object.ncloudstorage.com/nks-download/nas-csi/pub/jpn/v2.0.1/nas-csi.yaml

NAS CSI driver details

StorageClass

StorageClass is an object that specifies each storage's policy and type. NAVER Cloud Platform provides StorageClass which uses NAS volume.
To check the StorageClass object of NAS volume, check the object with the name of NKS-NAS-CSI. It will be shown as below.

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: nks-nas-csi
mountOptions:
- hard
- nolock
- nfsvers=3
provisioner: nas.csi.ncloud.com
reclaimPolicy: Delete
volumeBindingMode: WaitForFirstConsumer
allowVolumeExpansion: true

• volumeBindingMode: the point of action for volume binding and dynamic provisioning can be set. The default is Immediate.

• reclaimPolicy: you can set the policy so that the PersistentVolume in use is secured again or deleted when PVC is deleted at the end of its use. The default is Delete.

• allowVolumeExpansion: PersistentVolumeClaim can be extended by setting this value to true.

Change default storage class

To change the default storage class content of a created StorageClass object, Changing the default StorageClass.

CSI Controller

CSI controller is an interface that takes charge of various controls and management of a volume such as creation, deletion, assignment, removal from assignment, snapshot, etc.

To check the NAS CSI controller, use the command shown below to check the deployment object in the kube-system namespace.

$ kubectl --kubeconfig $KUBE_CONFIG get deployment -n kube-system

CSI Node

CSI node is a node corresponding to each of Kubernetes worker nodes. It's in charge of actions such as volume format, mounting, unmounting, etc.

To check NAS CSI node, use the command shown below to check the DaemonSet resource in the kube-system namespace.

$ kubectl --kubeconfig $KUBE_CONFIG get daemonset -n kube-system

Use CSI driver

Add NAS volume

To add NAS volume through NAS CSI driver, request PersistentVolumeClaim (PVC) through the following yaml code. NAS CSI driver checks the PVC and automatically generates the necessary PersistentVolume (PV).

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: nas-csi-pvc
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 500Gi
  storageClassName: nks-nas-csi

• AccessMode: NAS CSI supports various access modes.

• Resources: size of the storage to be created. The default value is 500 GB, and Gi can be used to enter a value between 500 GB to 10,000 GB in the units of 100 GB.

Assign a new volume to a pod

Use the following yaml code to create a new NAS volume and mount it.

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: nas-csi-pvc
spec:
  accessModes:
  - ReadWriteMany
  resources:
    requests:
      storage: 500Gi
  storageClassName: nks-nas-csi
---
kind: Pod
apiVersion: v1
metadata:
  name: my-csi-app
spec:
  containers:
    - name: my-frontend
      image: busybox
      volumeMounts:
      - mountPath: "/data"
        name: my-volume
      command: [ "sleep", "1000000" ]
  volumes:
    - name: my-volume
      persistentVolumeClaim:
        claimName: nas-csi-pvc

• Pod
  • spec.container: enter the storage name to be mounted to volumeMounts, and enter the mounting path to mountPath.
  • spec.volumes: enter the name of PersistentVolumeClaim to persistentVolumeClaim.claimName to define the storage to be mounted to the container.

Mount an already created NAS volume to a pod

NAS creates a volume with NFS protocol.

• Use NAS

Once a NAS volume is created, check the IP address and path information in the mount information.

Use the yaml code shown below to create a StorageClass using the already created NAS volume and mount it to a pod.

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: static-nks-nas-csi
provisioner: nas.csi.ncloud.com
parameters:
  server: __NAS_IP__
  share: __NAS_PATH__
reclaimPolicy: Retain
volumeBindingMode: WaitForFirstConsumer
mountOptions:
  - hard
  - nolock
  - nfsvers=3
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: static-pvc
spec:
  accessModes:
  - ReadWriteMany
  resources:
    requests:
      storage: 500Gi
  storageClassName: static-nks-nas-csi
---
kind: Pod
apiVersion: v1
metadata:
  name: my-csi-app
spec:
  containers:
    - name: my-frontend
      image: busybox
      volumeMounts:
      - mountPath: "/data"
        name: my-volume
      command: [ "sleep", "1000000" ]
  volumes:
    - name: my-volume
      persistentVolumeClaim:
        claimName: static-pvc

• kind: StorageClass
  Enter the information to use an existing NAS volume in Kubernetes cluster.
  
  • provisioner: enter nas.csi.ncloud.com, the Provisioner of the NAS volume of the NAVER Cloud platform.
  • parameters.server: enter the IP of the already created NAS volume mount information.
  • parameters.path: enter the path of the already created NAS volume mount information.
  • reclaimPolicy: you must set it to Retain to prevent the NAS volume from being deleted when a PVC that has been used is deleted.
• kind: PersistentVolumeClaim
  Create PersistentVolumeClaim to bind with the created PersistentVolume.
  • resources.storage: this is a required field. Enter the size of the NAS volume previously created. However, the PVC size is dependent to the NAS volume size, so the entered value is meaningless.
  • storageClassname: enter static-nks-nas-csi, which is the name of the NAS storage class.
  • volumeName: enter the name of the created PersistentVolume.
• kind: Pod
  Specify PersistentVolumeClaim which is a volume request to mount the volume to use.
  • volumes.persistentVolumeClaim.claimName: enter a name for the PersistentVolumeClaim to specify.

Remove PersistentVolumeClaim

Kubernetes’ PersistentVolumeClaim is not deleted, even when the request resources are deleted such as Deployment, StatefulSet, ReplicaSet, Pod, etc. A separate command is required to delete it.

Use the following commands separately to check PersistentVolumeClaim and to remove it.

• View PVC

$ kubectl --kubeconfig $KUBE_CONFIG get pvc

• Delete PVC

$ kubectl --kubeconfig $KUBE_CONFIG delete pvc static-pvc

Resize volume

NAVER Cloud Platform's NAS volume provides the resizing feature for the already created volumes.

The following describes how to resize a NAS volume. The example below uses a NAS volume of 500 GB in size.

1. Use the yaml code shown below to create a new block storage volume of 500 GB.
   

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: csi-deployment-pvc
spec:
  accessModes:
  - ReadWriteMany
  resources:
    requests:
      storage: 500Gi
  storageClassName: nks-nas-csi
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-csi-app
spec:
  selector:
    matchLabels:
      app: my-csi-app
  replicas: 1
  template:
    metadata:
      labels:
        app: my-csi-app
    spec:
      containers:
        - name: my-frontend
          image: busybox
          volumeMounts:
          - mountPath: "/data"
            name: my-volume
          command: [ "sleep", "1000000" ]
      volumes:
        - name: my-volume
          persistentVolumeClaim:
            claimName: csi-deployment-pvc

2. Run the command shown below to adjust PersistentVolumeClaim's volume request size from 500 GB to 600 GB.

kubectl --kubeconfig $KUBE_CONFIG patch pvc csi-deployment-pvc -p '{"spec":{"resources":{"requests":{"storage":"600Gi"}}}}'

Use StorageClass with the Zone Number Specified

The NAS CSI driver creates an NAS volume in the same zone as Kubernetes. However, you can create a NAS volume in a specific zone in the same region by specifying zoneNo in StorageClass. You can create an NAS volume by specifying ZoneNo through the yami code, which is used as an example below.

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: nks-nas-csi-kr-2
mountOptions:
- hard
- nolock
- nfsvers=3
provisioner: nas.csi.ncloud.com
parameters:
  zoneNo: "3"
reclaimPolicy: Delete
volumeBindingMode: WaitForFirstConsumer
allowVolumeExpansion: true
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: nas-csi-pvc
spec:
  accessModes:
  - ReadWriteMany
  resources:
    requests:
      storage: 500Gi
  storageClassName: nks-nas-csi-kr-2
---
kind: Pod
apiVersion: v1
metadata:
  name: my-csi-app
spec:
  containers:
    - name: my-frontend
      image: busybox
      volumeMounts:
      - mountPath: "/data"
        name: my-volume
      command: [ "sleep", "1000000" ]
  volumes:
    - name: my-volume
      persistentVolumeClaim:
        claimName: nas-csi-pvc

• kind: StorageClass

  • parameters.zoneNo: enter ZoneNo for creating an NAS volume.

    Region	Zone	ZoneNo
    Korea	KR-1	2
    Korea	KR-2	3
    Singapore	SGN-4	74
    Singapore	SGN-5	75
    Japan	JPN-4	84
    Japan	JPN-5	85