You can export custom images for on-premises testing or for Apsara stack environments.

Note
  • The time it takes to export an image depends on the size of the image file and the number of export tasks in the queue.
  • Exported images are stored in your OSS bucket. This means you are billed for the OSS storage and download traffic. For more information, see OSS billing items.

Limitations

Currently, the image export function has the following limitations:

  • You cannot export custom images that are created by a system disk snapshot from the Alibaba Cloud Marketplace.
  • You can export the custom images that contain four snapshots of data disks at most, and for a single data disk, the maximum volume must be no greater than 500 GiB.
  • When using exported custom images to create an instance by using the wizard, you must confirm that the file device recorded in /etc/fstab corresponds to the exported data disk snapshot information.

Prerequisites

Before exporting a custom image, you must:

  • Open a ticket to activate the image export feature, and describe the use cases of the exported images in the ticket.
  • Activate OSS and make sure that the region where your custom images are located has an available OSS bucket. For more information, see create a bucket.

Procedure

To export a custom image in the ECS console, follow these steps:

  1. Log on to the ECS console.
  2. In the left-side navigation pane, choose Snapshot & Images > Images.
  3. Select the target region.
  4. Find the custom image you want to export and then, in the Actions column, click Export Image.
    1. In the Export Image dialog box, click Conform Address.
    2. In the Cloud Resource Access Authorization window, click Confirm Authorization Policy to allow ECS to access your OSS resources.
  5. Return to the ECS console homepage. In the Actions column of the Images page, click Export Image again.
  6. In the Export Image dialog box:
    • Select the OSS bucket in the specified region.
    • Set the prefix of the object name of the exported image. For example, if you set Demo as the prefix, then the exported image file displayed in the OSS bucket is named Demo-[automatically generated file name].
  7. Click OK.
  8. (Optional) Cancel the image export task. Before the task is completed, you can go to the Tasks management page in the ECS console, find the relevant task in the specified region and cancel the task.

You can also use the ECS APIs ExportImage and CancelTask to perform the preceding operations.

Next steps

When an exported custom image contains a data disk snapshot, multiple files appear in your OSS. The file name with system indicates a system disk shapshot and the file name with data indicates a data disk snapshot. A data disk snapshot has an identifier corresponding to the data disk, which is the mount point of the data disk, such as xvdb or xvdc.

  1. Log on to the OSS console to query the export result.
  2. After the custom image is exported successful, download the object and then download the custom image file.
    Note The format of the image file is RAW by default. However, the .tar.gz format is also available during the gated launch period, and the file is in the .raw format after you unzip the .tar.gz file. If you are using Mac OS X operating system, the agent gnu-tar is recommended to unzip the file.