Rootfs

A roofs provides ephemeral storage for your workload. It is ideal for content like buffers, caches, scratch data, and other temporary data.

rootfs is associated with container, instead of pod. Everyone container comes with its own dedicate rootfs. If a pod has only one container, there is only one rootfs in that pod; if a pod has four containers, there will be four rootfs in the pod.

rootfs use the EXT4 filesystem. The size is fixed: 10GB.

Lifecycle

There is no way to control rootfs, or view it in the web console. However, the following are some principles:

• rootfs is created and mounted automatically to the pod. You don't need to specify rootofs when you launch pods.

• rootfs is always mounted at the root path / in the container. There is no way to change that.

• You can't detach a rootfs from one pod and attach it to a different pod.

• The data in rootfs persists only during the lifetime of its associated pod. If the pod is restarted, data in the rootfs is reset.

• Currently there is no way to commit changes in a rootfs to a new Docker image.

Billing

• A pod may have one or more containers.

• Every container come with a default 10GB rootfs, e.g. if a pod have 3 containers, the pod has three rootfs, 30GB in total.

• Rootfs exits along with the lifecycle of the pod. Billing begins when the pod is created, ends when the pod terminates or exists.

• The price is $0.0000000386/GB/second, and a default duration of 60 seconds is applied.