An ECS image stores information that you need for creating an ECS instance. You must select an image when you create an ECS instance. An image works as a copy that stores data from one or more disks. An ECS instance image may store data from a system disk or from both system and data disks.
Image types
ECS images are classified into public images, custom images, shared images, and Alibaba Cloud Marketplace images based on image sources.
- Public images
Public images provided by Alibaba Cloud are licensed, secure, and stable. Public images include Windows Server system images and mainstream Linux system images. For more information, see Public images.
- Custom images
Custom images are created from instances or snapshots, or imported from your local device. For more information, see Custom images.
- Shared images
Shared images are shared with you by other Alibaba Cloud accounts. For more information, see Shared 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 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 of different types of images.
| Type | Price |
|---|---|
| Public image |
A portion of public images are billed while others are free of charge.
Note Public images that run Windows Server are licensed and maintained by Microsoft. Public
images that run Red Hat Enterprise Linux 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 based on the billing methods provided in Alibaba Cloud Marketplace.
|
| 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 based on the billing methods provided in Alibaba Cloud Marketplace.
|
| 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 in Image FAQ.
Select and find images
You can select an image based on the region, image type, image cost, 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 is created. Then, you can use the image to create an instance or perform other operations. For more information, see Find an image.
Replace the image of an ECS instance
After you create an ECS instance, you can change its operating system by replacing the system disk of the instance.
- You can replace the image with a public image by replacing the system disk of the instance. For more information, see Replace the system disk (public images).
- You can also replace the image with a non-public image such as a custom, shared, or Alibaba Cloud Marketplace image by replacing the system disk of the instance. For more information, see Replace the system disk (non-public images).
API operations
You can also call API operations to manage images. For more information, see the "Images" section in List of API operations by functions.