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    :Image FAQ

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    :Image FAQ

    Last Updated:May 15, 2026

    Common questions about creating, copying, encrypting, sharing, importing, exporting, and deleting ECS images.

    Creating images

    Copying images

    Encrypting images

    Sharing images

    Importing images

    Exporting images

    Deleting images

    Can I create a custom image from a data disk snapshot?

    No. Custom images can only be created from system disk snapshots, but you can include data disk snapshots when creating a custom image from a snapshot.

    How do I check image creation progress, and how long does it take?

    Check progress on the Images page of the ECS console. Creation time depends on total disk size. The image becomes available after a snapshot is created for each disk. See Create a custom image from an instance.

    When do I need to copy a custom image?

    Custom images are region-specific. Copy a custom image to:

    • Deploy applications across multiple regions.

    • Migrate an instance to another region.

    • Use a custom image across regions.

    • Change the encryption status of a custom image or encrypt system disk data.

    See Copy a custom image.

    Which images can be copied?

    Only custom images can be copied. Public images and Alibaba Cloud Marketplace images cannot.

    How long does it take to copy an image?

    Copy time depends on the network transfer rate and the queue depth, because the image file transfers between regions.

    For images over 2 TiB, copy the snapshots to the destination region and then create a custom image from those copies — this is faster than copying the image directly. Snapshot copying incurs storage and data transfer fees. See Snapshot billing.

    Can I copy a custom image derived from an Alibaba Cloud Marketplace image across regions?

    Only if the Alibaba Cloud Marketplace image exists in the destination region. Otherwise, the copy fails with an error like the one below.

    Marketplace image copy error

    Can I encrypt ECS instance system disks with Key Management Service (KMS) keys? How do I use Terraform or Packer?

    Yes. System disks can be encrypted with default service keys or custom keys in KMS. See Encrypt a system disk.

    What are the requirements for Copy and Encrypt?

    To use the Copy and Encrypt feature:

    1. Activate KMS.

    2. Set Copy Mode to Copy and Encrypt.

    3. To use a custom KMS key, create a CMK (Customer Master Key) first.

    What permissions are required to share an encrypted image?

    Create a RAM role named AliyunECSShareEncryptImageDefaultRole and grant the required permissions before sharing an encrypted image with other accounts or within your resource directory. See Share an encrypted custom image.

    Can I share images between China site and international site accounts?

    No. Images cannot be shared between accounts on the China site and accounts on the international site.

    What are the risks of sharing images?

    • Data leakage and software theft. Verify that the image contains no sensitive data or software before sharing. Recipients can create instances from the shared image and generate additional custom images, spreading data through this chain.

    • Security of received images. Alibaba Cloud does not guarantee the integrity or security of images shared by other accounts. Use only images from trusted accounts and verify security after creating an instance.

    • Impact of deletion. If the image owner deletes a shared image, the system disks of instances created from that image can no longer be re-initialized.

    Can I re-share an image that was shared with me?

    No. Copy the shared image to create your own custom image, then share that image.

    How do I share an image across regions?

    Two approaches:

    • Share the image first, then have the recipient copy it to the destination region.

    • Copy the image to the destination region first, then share the copy.

    See Copy a custom image and Share a custom image.

    How do I check import progress, and how long does it take?

    Check the Images page or the Task Logs page in the ECS console for the target region.

    Import time depends on the image size and the queue depth. See Import a custom image.

    My Bring Your Own License (BYOL) image licenses have expired. How do I switch to Alibaba Cloud licenses?

    Replace the BYOL image by replacing the instance operating system:

    Can I use an Object Storage Service (OSS) internal endpoint to import custom images?

    No. Use the public URL generated when you share the image object. Importing with an internal endpoint returns an error.

    How do I convert ISO files to ECS-supported image formats?

    Convert ISO files before import:

    1. Create an image from the ISO file on premises using a tool such as VirtualBox.

    2. Convert the image to a supported format: RAW, Virtual Hard Disk (VHD), QEMU Copy-On-Write version 2 (QCOW2), or Virtual Machine Disk (VMDK).

    See Import a custom image.

    Which image formats can be used in ECS?

    How do I upload on-premises image files to ECS?

    See Import a custom image.

    What permissions are required to upload image files to OSS?

    • Alibaba Cloud account: Upload directly.

    • RAM user: Ask the Alibaba Cloud account owner to grant permissions on the relevant OSS buckets.

    How do I download image files to an on-premises device?

    Export a custom image and download the file from OSS.

    Can an exported ECS image boot on other platforms?

    Exported ECS images may not boot on other platforms. To retrieve disk data, attach the disks from the downloaded images to on-premises devices.

    What should users do if they want to export a public image?

    ECS supports exporting custom images but not public images directly. To export a public image, create a custom image from it first, then export the custom image.

    Can I delete a shared or in-use image? What happens if I do?

    A shared or in-use image can only be force deleted.

    If you delete Image M after sharing it with Account A:

    • Account A can no longer query Image M in the ECS console or through API operations.

    • Account A can no longer use Image M to create instances or replace system disks.

    • The system disks of instances that Account A created from Image M can no longer be re-initialized.

    See Delete a custom image.

    Why do I see "The specified image cannot be deleted because it is associated with instances"?

    The image was used to create ECS instances. Select Forcefully Delete Image to proceed. After force deletion, existing instances remain available, but their system disks cannot be re-initialized. See Delete a custom image.

    Why does `curl vpc network mirror site domain http://mirrors.cloud.aliyuncs.com/` redirect to the internet https://developer.aliyun.com/mirror/?

    Only the homepage redirects to the public network. The URL redirect is set in the HTTP header location. Appending a system path such as CentOS or Alinux after the domain http://mirrors.cloud.aliyuncs.com/ still uses the internal network link for downloads.