Container Compute Service:Add the EphemeralStorage

Background information

By default, each ACS pod provides 30 GiB of free ephemeral storage space, as displayed in the following figure.

Billing

When the EphemeralStorage exceeds 30 GiB, the overage is billed based on the billing rules of disks.

Fee = Unit price of disks × Ephemeral storage overage × Duration.

• Unit price of disks: the pay-as-you-go price of PL1 ESSDs. For more information about the unit prices of disks in different regions, see EBS pricing.

• Ephemeral storage overage: the additional storage space that you declared.

• Duration: the duration that is measured in seconds. The EphemeralStorage is created and released together with the ACS pod and its uptime equals the uptime of the ACS pod.

How to configure

ACS allows you to use the following two methods to add the EphemeralStorage to an ACS pod.

• Method 1 (recommended): Add an annotation

  You can add the alibabacloud.com/extra-ephemeral-storage annotation when creating an ACS pod to declare the size of the EphemeralStorage.

• Method 2: Configure the container resource

  You can declare the size of the EphemeralStorage in .resources.requests.ephemeral-storage of the ACS pod when creating the pod. If the EphemeralStorage size is smaller 30 GiB, the actual EphemeralStorage is automatically expanded to 30 GiB. If the EphemeralStorage size exceeds 30 GiB, the overage is the additional storage space.

Examples

For example, you want to add 20 GiB of ephemeral storage space to an ACS pod. In this case, EphemeralStorage = Default 30 GiB + Additional 20 GiB = 50 GiB.

1. Create a YAML file named extra-storage.yaml based on the following content.

   Method 1: Add an annotation

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: test
     labels:
       app: nginx
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: nginx
     template:
       metadata:
         labels:
           app: nginx
         annotations:
           alibabacloud.com/extra-ephemeral-storage: "20Gi"  # Declare the additional storage space.
       spec:
         containers:
         - name: nginx
           image: registry.cn-hangzhou.aliyuncs.com/acs-sample/nginx:latest
           ports:
           - containerPort: 80

   Method 2: Configure the container resource

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: test
     labels:
       app: nginx
   spec:
     replicas: 1
     selector:
       matchLabels:
         app: nginx
     template:
       metadata:
         labels:
           app: nginx
       spec:
         containers:
         - name: nginx
           image: registry.cn-hangzhou.aliyuncs.com/acs-sample/nginx:latest
           ports:
           - containerPort: 80
           resources: 
             requests: 
               ephemeral-storage: 50Gi   #  Declare the size of the EphemeralStorage.

2. Create a workload.

   kubectl apply -f extra-storage.yaml

3. View the pod deployment.

   kubectl get pod

   Expected output:

   NAME                  READY   STATUS    RESTARTS   AGE
   test-ff8767b7b-****   1/1     Running   0          54s

4. Check whether the EphemeralStorage takes effect.

   1. View the pod annotation to confirm the size of the EphemeralStorage.

      The value of alibabacloud.com/pod-ephemeral-storage indicates the ephemeral storage space of the ACS pod in GiB.

      kubectl describe pod test-ff8767b7b-**** | grep alibabacloud.com/pod-ephemeral-storage

      The output indicates that the size of the EphemeralStorage is 50 GiB.

      alibabacloud.com/pod-ephemeral-storage: 50Gi

   2. Run the exec command to log on to a container and then run the df -h command to check whether the file system partition is expanded.

      kubectl exec -it test-ff8767b7b-**** -- sh
      df -h

      The output indicates that the actual available storage space (overlay) is 50 GiB.

      Filesystem      Size  Used Avail Use% Mounted on
      overlay          50G  2.7G   45G   6% /
      tmpfs            64M     0   64M   0% /dev
      tmpfs           2.8G     0  2.8G   0% /sys/fs/cgroup
      /dev/vda5        50G  2.7G   45G   6% /etc/hosts
      shm              64M     0   64M   0% /dev/shm
      tmpfs           4.0G   12K  4.0G   1% /run/secrets/kubernetes.io/serviceaccount
      tmpfs           2.8G     0  2.8G   0% /proc/acpi
      tmpfs           2.8G     0  2.8G   0% /proc/scsi
      tmpfs           2.8G     0  2.8G   0% /sys/firmware