Mount a NAS file system by using a built-in Kubernetes volume - File Storage NAS

This topic describes how to use a built-in Kubernetes volume to mount a File Storage NAS (NAS) file system on a Kubernetes cluster.

Prerequisites

A Network File System (NFS) file system is created. For more information, see Create a file system.
To encrypt data in a NAS file system, you must configure the encryption type when you create the NAS file system.
A mount target is created. For more information, see Manage mount targets.
A self-managed Kubernetes cluster is created and the cluster version is 1.16 or later.
Port 111 and port 2049 are specified in the security group rule of the pod scheduling node. For more information, see Add a security group rule.
If the self-managed Kubernetes cluster is deployed in a data center, the data center must be connected to Alibaba Cloud. You can connect the data center to Alibaba Cloud by using Express Connect, Smart Access Gateway (SAG), or VPN Gateway. For more information, see the following topics:

Limits

The limits on mounting scenarios, the number of file systems, and file sharing protocols vary with the storage class of NAS file systems. For more information, see Limits.

Important

Before you unmount a NAS file system, do not delete the mount target of the file system. Otherwise, an operating system hang may occur.

Procedure

Log on to the self-managed Kubernetes cluster.
Configure the nodes in the Kubernetes cluster.
Note
You must configure all nodes in the Kubernetes cluster. Before you add a node to the Kubernetes cluster, you must perform the following steps.
1. Install an NFS client. For more information, see Step 1: Install an NFS client.
2. Run the following command to configure the /etc/nfsmount.conf file:
```
cat <<EOF >> /etc/nfsmount.conf
[ Server "file-system-id.region.nas.aliyuncs.com" ]
vers=3
Proto=tcp
Lock=False
resvport=False
rsize=1048576
wsize=1048576
hard=True
timeo=600
retrans=2
EOF
```
  In the preceding command, file-system-id.region.nas.aliyuncs.com is the domain name of the mount target for the NAS file system. Replace the domain name with the actual value. To obtain the domain name of the mount target, perform the following steps: Log on to the NAS console. On the File System List page, click the ID of the file system. On the details page, click the Mount Targets tab. Then, move the pointer over the icon in the Mount Target column.
  Note
  We recommend that you use the NFSv3 protocol to mount a NAS file system.
  All the parameters in the preceding command are required. You do not need to modify other parameters except the file-system-id.region.nas.aliyuncs.com and vers parameters. The vers parameter specifies the protocol version.
3. Verify that the NAS file system is connected to the Kubernetes cluster.
  1. Run the following command to mount the NFS file system:
```
mount -t nfs file-system-id.region.nas.aliyuncs.com:/ /mnt 
```
    In the preceding command, file-system-id.region.nas.aliyuncs.com is the domain name of the mount target for the NAS file system. Replace the domain name with the actual value.
    If the mount fails, ping the domain name of the mount target and check whether port 2049 is connected. If the mount failure is not caused by network issues, use the script tool to troubleshoot the issue. For more information, see Run the auto-check script to troubleshoot the failure of mounting an NFS file system on Linux.
  2. Run the following command to view the mount information:
```
mount | grep nfs | grep mnt 
```
    If the parameters include vers=3, hard, noresvport, and nolock, the network is connected.
    After you confirm that the network is connected, run the umount /mnt command to delete the mounted NFS file system.

Start a pod to mount the NFS file system by using a built-in Kubernetes volume.

In this example, a pod named nginx is started to mount the NFS file system.

Configure the nginx.yaml file.

cat  << EOF > ./nginx.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  selector:
    matchLabels:
      app: nginx
  replicas: 1
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.14.2
        ports:
        - containerPort: 80
        volumeMounts:
        - mountPath: /data
          name: test-nfs
      volumes:
      - name: test-nfs
        nfs:
          server: file-system-id.region.nas.aliyuncs.com    # The domain name of the mount target for the NAS file system. Replace the domain name with the actual value. Example: 7bexxxxxx-xxxx.ap-southeast-1.nas.aliyuncs.com. 
          path: /    # The directory path of the NAS file system. The directory must be an existing directory or the root directory. The root directory of a General-purpose NAS file system is "/". The root directory of an Extreme NAS file system is "/share". 
EOF

Enable the nginx pod to use the NFS file system.
```
kubectl apply -f ./nginx.yaml
```

Check whether the pod is started as expected and whether the NFS file system is mounted.
1. Run the following command to check the status of the pod.
  - Command
```
kubectl get pods | grep nginx 
```
  - Output
    If the pod is in the Running state, the pod is started as expected.
2. Run the following command to view the mount result.
  - Command
```
kubectl exec nginx-deployment-9b9b684f5-mgrkh  -- df -h /data
```
  - Output
    If an output similar to the following example appears, the mount is successful.