An Elastic Compute Service (ECS) image provides information necessary to create an ECS instance. You must select an image when you create an ECS instance. An image is a copy of data from one or more disks. An instance image can contain data from a system disk or from both system and data disks.
Image types
- Public images
Public images provided by Alibaba Cloud are licensed, secure, and stable. Public images for Windows Server operating systems and mainstream Linux operating systems are provided. For more information, see Overview.
- Custom images
Custom images are created from instances or snapshots or imported from your computer. When the system creates a custom image from snapshots or from an instance, it copies the snapshots or creates snapshots of the system disk and data disks of the instance. You are charged for the snapshots contained in the custom image. For more information, see Overview.
- Shared images
Shared images are shared to you by other Alibaba Cloud accounts. Images shared to an account do not count against the image quota for the account. The account does not incur charges for images shared to it. For more information, see Share or unshare custom images.
- Alibaba Cloud Marketplace images
Alibaba Cloud Marketplace images are classified into the following types based on their providers:
- Images provided by Alibaba Cloud
- Images provided by independent software vendors (ISVs) that are licensed by Alibaba Cloud Marketplace
An Alibaba Cloud Marketplace image contains an operating system and pre-installed software. The operating system and pre-installed software are thoroughly tested and verified by the ISV and Alibaba Cloud to ensure that the image is safe to use. For more information, see Alibaba Cloud Marketplace images.
Image prices
You may be charged for using images. The following table describes the billing methods for different image types.
| Image type | Price |
|---|---|
| Public image | Some public images are billed, whereas others are free of charge.
Note Windows Server public images are licensed and maintained by Microsoft. Red Hat Enterprise Linux public images are licensed and maintained by Red Hat.
|
| Custom image | Custom images are billed differently in the following situations:
Note If a custom image is derived from an Alibaba Cloud Marketplace image, the custom image is billed in the same manner as the Alibaba Cloud Marketplace image.
|
| Shared image | Shared images are billed differently in the following situations:
Note If a shared image is derived from an Alibaba Cloud Marketplace image, the shared image is billed in the same manner as the Alibaba Cloud Marketplace image.
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| Alibaba Cloud Marketplace image | Alibaba Cloud Marketplace images are billed based on the billing methods provided in Alibaba Cloud Marketplace. |
For more information, see Billing overview and the "FAQ about commercial availability of images" section of the Image FAQ topic.
Select and find images
You can select an image based on the region, image type, image price, operating system, and built-in software. For more information, see Select an image.
You can find an image based on its type, name, ID, or the ID of the snapshot from which the image was created. Then, you can use the image to create instances or perform other operations. For more information, see Find an image.
Replace the image of an instance
After you create an instance, you can replace its operating system by replacing its system disk.
- You can replace the image of the instance with a public image when you replace the system disk. For more information, see Replace the system disk (public images).
- You can also replace the image of the instance with a non-public image such as a custom, shared, or Alibaba Cloud Marketplace image when you replace the system disk. For more information, see Replace a system disk (non-public images).
API operations
You can also call API operations to manage images. For more information, see the "Images" section of the List of API operations by function topic.