Image Instant Access enables an image to become usable within seconds after creation. You can use the image to create instances, replace system disks, or reinitialize system disks without waiting for the image progress to reach 100%. - Elastic Compute Service

The more data that is stored in a disk (or snapshot), the longer it takes to create an image. Image Instant Access allows an image to become usable within seconds after creation. This means that you can use the image directly without waiting for the image progress to reach 100%.

Overview

With Image Instant Access, you can use the following features before the image progress reaches 100%:

Billing

Image Instant Access is free of charge.

Limits

Image Instant Access is supported only for images created from instances that contain ESSD-series disks or from snapshots created from ESSD-series disks.
When the conditions are met, Image Instant Access is enabled by default when you create an image. You cannot manually enable or disable it.

API behavior

API operation	Feature	Image Instant Access behavior
CreateImage	Creates an image.	Supports creating an Image Instant Access image from a qualified instance or snapshot.
RunInstances	Creates multiple instances at a time.	Supports using an Image Instant Access image to create multiple instances immediately, without waiting for the image progress to reach 100%.
CreateInstance	Creates an instance.	Supports using an Image Instant Access image to create an instance immediately, without waiting for the image progress to reach 100%.
ReplaceSystemDisk	Replaces the system disk.	Supports using an Image Instant Access image to replace the system disk immediately, without waiting for the image progress to reach 100%.
ReInitDisk	Reinitializes the system disk.	Supports using an Image Instant Access image to reinitialize the system disk immediately, without waiting for the image progress to reach 100%.
DescribeImages	Queries images.	Adds the `Usable` field, which indicates whether an image is usable. The query result returns the `Usable` field, and you can filter by `Usable = true/false`.
ModifyImageSharePermission	Shares an image.	After an image is shared, the recipient can also use Image Instant Access.
DeleteImage	Deletes an image.	Supports deleting an Image Instant Access image.

How to determine whether an image is usable

After an image becomes usable, the response of the DescribeImages operation contains the following information:

Usable: indicates whether the image can be immediately used in scenarios such as creating instances.
- Usable = true: The image is usable (even if its Status is not Available).
- Usable = false: The image is not yet usable.

Use Image Instant Access

Image Instant Access is enabled by default when you create a qualified image. No manual configuration is required, and it cannot be disabled. For more information about how to create an image, see Create a custom image from an instance.

FAQ

What are the differences between an Image Instant Access image and a regular image?

Availability time: An Image Instant Access image is usable within seconds after creation, whereas a regular image requires the progress to reach 100%.
Status display: When Usable=true, the status of an Image Instant Access image may not be Available (for example, Waiting or Creating). A regular image must be in the Available state.
Applicable scenarios: An Image Instant Access image is applicable only to certain time-sensitive scenarios that support instant access, whereas a regular image is applicable to all scenarios. For example, you cannot use an Image Instant Access image to copy an image.