Help Center/ Cloud Container Instance (CCI)/ User Guide/ Using CCI Through the Console/ Images/ Image Snapshots/ Image Snapshot Overview
Updated on 2026-04-28 GMT+08:00
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Image Snapshot Overview

Images from SWR or third-party image repositories (such as open-source repositories or self-managed repositories) can be used to create image snapshots. After image snapshots are created, they can be used to create workloads, and there is no need to pull the images. This speeds up workload startup.

When creating a pod, you can use an image snapshot to avoid image download and reduce the pod startup time. This section describes the constraints on image snapshots and how you can use them.

Constraints

  • An image snapshot can contain a maximum of 10 images.
  • Private image repositories are supported. However, the access credentials of private image repositories must be provided, including the address and authentication information, such as the auth information in ~/.docker/config.json.
  • If the image needs to be pulled over the public network, you need to specify the public network access configuration in advance.
  • If only some images in an image snapshot are consistent with those for the pod, inconsistent images still need to be pulled.
  • If the image of a running pod changes and the new image is inconsistent with any image in the image snapshot, the new image needs to be pulled.
  • By default, a CCI pod with 2 vCPUs and 4 GiB of memory will be used to create an image snapshot. You will be billed for this pod.

Image Snapshot Creation Methods

An image snapshot can be created manually or automatically.

  • Manual creation

    You can create an image snapshot by configuring the parameters such as the image snapshot name and image size. The following figure shows the process.

  • Automatic creation

    When you create a CCI pod, you can enable automatic image snapshot creation. If no image snapshot is matched, CCI automatically creates an image snapshot while creating the CCI pod. The following figure shows the process.

    It takes some time to create an image snapshot. As a result, the CCI pod created before the image snapshot is created cannot use the image snapshot.

Manually-created image snapshots differ from automatically-created image snapshots in many aspects such as the image size and image snapshot retention period. For details, see Table 1.

Table 1 Comparison between manually-created and automatically-created image snapshots

Item

Manual Creation

Automatic Creation

Name

User-defined

Unique for each tenant and prefixed with auto-create-by-cci

Expiration time

User-defined. The default value is 0, indicating that the snapshot never expires.

30 days

Image snapshot size

User-defined. The default value is 20 GiB.

20 GiB

Image list

User-defined

All images of the pod you create

Namespace of the temporary pod created during image snapshot creation

User-defined

Namespace of the pod you create

HTTP for access to the image repository

User-defined. The default protocol is HTTPS.

Not supported. The default protocol is HTTPS.

Skipping client certificate verification when HTTPS is used for access to the image repository

User-defined. The client certificate is verified by default.

Not supported. The client certificate is verified by default.

Access secret

User-defined

ImagePullSecrets configured for the pod you create

Network settings

EIP used for pulling images over the public network

User-defined

Not supported

Whether to automatically assign an EIP for the pod that is used for creating the image snapshot

User-defined. By default, no EIP is assigned.

If an EIP is automatically assigned to the pod you create, an EIP is also assigned to the temporary pod for creating the image snapshot.

Billing by traffic or bandwidth

User-defined. By default, billing by bandwidth is used.

Same as the billing mode configured when the EIP is automatically assigned for the pod you create

Bandwidth

User-defined

Same as the bandwidth configured when the EIP is automatically assigned for the pod you create

EIP type

User-defined

Same as the EIP type configured when the EIP is automatically assigned for the pod you create

EIP version

User-defined. The default version is IPv4.

EIP version configured when the EIP is automatically assigned for the pod you create

Creating a Pod Using an Image Snapshot

You can use an image snapshot to create a pod in either of the following ways:

  • Method 1: Automatic matching

    The optimal image snapshots are selected from all available image snapshots based on the following:

    1. Image matching degree: The images in the image snapshots are matched with those used by the pod, and the most matched image snapshots are preferred.
    2. Time when image snapshots were created: The latest image snapshot is preferred.
  • Method 2: Specifying the image snapshot

    You can specify the image snapshot to be used.

Parent Topic: Image Snapshots