After you create an Elastic Compute Service (ECS) instance, you can customize the instance by performing operations such as installing software and deploying application environments and then create a custom image from the instance. Instances created from the custom image contain all of the customized items. This eliminates the need to configure these items for each new instance.
Prerequisites
- An ECS Linux instance is created. For more information, see Create an instance by using the wizard.
- Sensitive data is deleted from the instance to enhance data security.
- Before you create a custom image from a Linux instance, the following items are checked:
- Network configurations of the instance. The network configurations are checked based on your Linux distribution. For more information, see How to solve unreachable network errors when a VPC-type instance is created from a custom image.
- Free space on the system disk. The system disk must have sufficient free space.
Background information
When you create a custom image from an instance, a snapshot is automatically created for each disk on the instance. All the snapshots together constitute a complete custom image, as shown in the following figure.

You can use one of the following methods to create a custom image from an instance:
Precautions
Before you create a custom image from an instance, take note of the items described in the following table.
Item | Description |
---|---|
Limits on regions | A custom image resides within the same region as the instance from which the image was created. For information about how to use images across regions, see Copy an image. |
Billing |
|
Instance type | You cannot create images that contain snapshots of system disks and data disks from instances that use local SSDs. For more information, see Overview. |
Instance status |
|
Linux instance |
When you create a custom image from a Linux instance, take note the following additional items:
|
Amount of time required to create an image | The amount of time it takes to create an image from an instance depends on the disk size of the instance. Wait until the snapshot for each disk is created before you can use the image. |
Create a custom image on the Images page
- Log on to the ECS console.
- In the left-side navigation pane, choose .
- In the top navigation bar, select a region.
- In the Create Image section, click Create Custom Image.
- In the Create Custom Image dialog box, configure the parameters described in the following table.
Parameter Description References Creation Method Select Instance. N/A Instance Select a created ECS instance from the drop-down list. N/A Image Name Enter a name for the custom image. N/A Image Family Optional. Select an image family when you create a custom image. Custom images that belong to an image family can be deprecated or restored to allow smooth image updates and rollbacks.
Overview Image Description Optional. Enter a description for the custom image. N/A Tag Select one or more tags. - Tag is an optional parameter in most scenarios.
- Tag is a required parameter when you log on as a Resource Access Management (RAM) user and a policy attached to the RAM user requires that tags be added. In this case, if you do not specify Tag, an error is reported and indicates insufficient permissions.
Overview Resource Group Optional. Select a resource group to manage the custom image based on usage and permissions. Resource groups - Click OK.
Create a custom image on the Instances page
- Log on to the ECS console.
- In the left-side navigation pane, choose .
- In the top navigation bar, select a region.
- Find the instance from which you want to create a custom image. In the Actions column, choose .
- In the Create Custom Image dialog box, configure the parameters described in the following table.
Parameter Description References Image Name Enter a name for the custom image. N/A Image Family Optional. Select an image family when you create a custom image. Custom images that belong to an image family can be deprecated or restored to allow smooth image updates and rollbacks. Overview Image Description Optional. Enter a description for the custom image. N/A Tag Select one or more tags. - Tag is an optional parameter in most scenarios.
- Tag is a required parameter when you log on as a RAM user and a policy attached to the RAM user requires that tags be added. In this case, if you do not specify Tag, an error is reported and indicates insufficient permissions.
Overview Resource Group Optional. Select a resource group to manage the custom image based on usage and permissions. Resource groups - Click OK.
What to do next
After the custom image is created, you can perform operations described in the following topics: