Create a custom image from a snapshot - Elastic Compute Service

You can create a custom image from a snapshot that contains the operating system and data of an Elastic Compute Service (ECS) instance. Then, you can use the custom image to create multiple identical instances.

Prerequisites

The snapshot service is activated, and a system disk snapshot is created. For more information, see Activate ECS Snapshot and Create a snapshot of a disk.
Sensitive data is deleted from the system disk snapshot to enhance data security.

Background information

You can use one of the following methods to create a custom image from a snapshot:

Create a custom image on the Images page
Create a custom image on the Instances page
Create a custom image on the Snapshots page

Precautions

Before you create custom images from snapshots, 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 snapshot from which the image was created. For information about how to use images across regions, see Copy an image.
Billing	A snapshot is automatically generated for each disk when you create a custom image. You are charged for the snapshots. For more information about snapshot billing, see Snapshots.
Snapshot	Only system disk snapshots can be used to create custom images and data disk snapshots cannot. Both encrypted and unencrypted snapshots can be used to create custom images. If the ECS instance from which a snapshot was created expires or is released, the custom image created from the snapshot and the ECS instance created from the image are not affected.
ECS instance	ECS instances created from custom images: You can upgrade the configurations of ECS instances created from custom images, such as vCPUs, memory, bandwidth, and disks. You can replace the operating systems of ECS instances created from custom images. The custom images are not affected and remain usable. For more information, see Replace the operating system of an instance by using a non-public image. Network connections in virtual private clouds (VPCs) may fail to establish for some ECS Linux instances that are created from custom images due to the configurations in /etc/sysconfig/network. For more information, see How to solve unreachable network errors when a VPC-type instance is created from a custom image.

Create a custom image on the Images page

Log on to the ECS console.
In the left-side navigation pane, choose Instances & Images > Images.
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 Snapshot.	N/A
Snapshot	Select a created system disk snapshot 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. Custom images that belong to an image family can be deprecated or restored to allow seamless image updates and rollbacks.	Overview
Snapshot Details	Optional. Select increaseData Disk, click increases, and then select the ID of a data disk snapshot. If you leave the Snapshot ID field empty, an empty data disk will be created when you use the custom image to create an instance. By default, the data disk is 5 GiB in size. If you select the ID of a data disk snapshot, the capacity of the data disk to be created is the same as the snapshot size.	Snapshot overview
Image Description	Enter a description for the custom image.	N/A
Tag	Select one or more tags. Tag is an optional parameter in most cases. 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 the 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 Instances & Images > Instances.
In the top navigation bar, select a region.
Find the instance whose snapshot you want to use and click the instance ID to go to the Instance Details page.
On the Instance Details page, click the Snapshot tab.
Find a snapshot whose Disk Type is System Disk and click Create Custom Image in the Actions column.

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. Custom images that belong to an image family can be deprecated or restored to allow seamless image updates and rollbacks.	Overview
Snapshot Details	Optional. Select increaseData Disk, click increases, and then select the ID of a data disk snapshot. If you leave the Snapshot ID field empty, an empty data disk will be created when you use the custom image to create an instance. By default, the data disk is 5 GiB in size. If you select the ID of a data disk snapshot, the capacity of the data disk to be created is the same as the snapshot size.	Snapshot overview
Image Description	Enter a description for the custom image.	N/A
Tag	Select one or more tags. Tag is an optional parameter in most cases. 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 the usage and permissions.	Resource groups

Click OK.

Create a custom image on the Snapshots page

Log on to the ECS console.
In the left-side navigation pane, choose Storage & Snapshots > Snapshots.
In the top navigation bar, select a region.
On the Disk Snapshots tab, find a snapshot whose Disk Type is System Disk and click Create Custom Image in the Actions column.

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. Custom images that belong to an image family can be deprecated or restored to allow seamless image updates and rollbacks.	Overview
Snapshot Details	Optional. Select increaseData Disk, click increases, and then select the ID of a data disk snapshot. If you leave the Snapshot ID field empty, an empty data disk will be created when you use the custom image to create an instance. By default, the data disk is 5 GiB in size. If you select the ID of a data disk snapshot, the capacity of the data disk to be created is the same as the snapshot size.	Snapshot overview
Image Description	Enter a description for the custom image.	N/A
Tag	Select one or more tags. Tag is an optional parameter in most cases. 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 the 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: