Expand Ephemeral Storage for ACS Pods - Container Compute Service

Each Alibaba Cloud Container Service (ACS) pod includes 30 GiB of free ephemeral storage by default. If your workload needs more space — for example, to accommodate large container images or high-volume log output — declare additional storage when creating the pod.

Important

The container image is stored in the pod's ephemeral storage. The space consumed by the image is at least two times the image size; the actual amount depends on the image's compression ratio. Account for this when sizing your ephemeral storage.

Billing

Storage beyond the default 30 GiB free tier is billed based on disk pricing:

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

Variable	Description
Unit price of disks	Pay-as-you-go price of PL1 ESSDs. For prices by region, see EBS pricing.
Ephemeral storage overage	The additional storage you declared above 30 GiB.
Duration	Measured in seconds. Ephemeral storage is created and released together with the pod.

Prerequisites

Before you begin, make sure that you have:

An ACS cluster with kubectl configured to connect to it
Permission to create Deployments in the target namespace

Configure ephemeral storage

Two methods are available. Use the annotation method (Method 1) unless you specifically need to control ephemeral storage through container resource specs.

Method 1 (recommended): Add an annotation

Add the alibabacloud.com/extra-ephemeral-storage annotation to the pod template. The value specifies additional storage on top of the default 30 GiB.

Method 2: Configure the container resource

Set the total ephemeral storage size in .resources.requests.ephemeral-storage on the container.

If the declared value is less than 30 GiB, ACS automatically expands the ephemeral storage to 30 GiB. Only storage declared above 30 GiB counts as overage for billing purposes.

Example: add 20 GiB of ephemeral storage

The following example declares an additional 20 GiB of ephemeral storage, bringing the total to 50 GiB (30 GiB default + 20 GiB additional).

Step 1: Create the YAML file

Create a file named extra-storage.yaml using one of the following methods.

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"  # Additional storage on top of the default 30 GiB.
    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   # Total ephemeral storage size (30 GiB default + 20 GiB additional).

Step 2: Create the workload

kubectl apply -f extra-storage.yaml

Step 3: Verify the pod is running

kubectl get pod

Expected output:

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

Step 4: Confirm the ephemeral storage size

a. Check the pod annotation.

The alibabacloud.com/pod-ephemeral-storage annotation shows the total ephemeral storage in GiB.

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

Expected output:

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

b. Check the container file system.

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

Expected output — the overlay row shows the 50 GiB root file system available to the container:

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