A custom image is a point-in-time backup of a Simple Application Server's disk—created from a snapshot—that captures the OS, applications, and data on that disk. Use custom images to launch multiple servers with identical configurations, or share them with Elastic Compute Service (ECS) to create ECS instances or replace the OS of an existing instance.
Lifecycle of a custom image
After you create a custom image, you can use it to create new servers, copy it to another region, or share it with ECS. Delete images you no longer need to keep your image library tidy. The following figure shows the lifecycle of a custom image.
Billing
Custom images are free of charge. Charges apply in the following cases:
Creating a server from a custom image: You are charged for the server resources consumed. For more information, see Billable items.
Creating an ECS instance from a shared custom image: You are charged for the ECS resources consumed. For more information, see Billing overview.
Use cases
| Scenario | Description |
|---|---|
| Server O&M | Scale out quickly by launching multiple servers from a single custom image. All servers start with identical OS, applications, and data—no repetitive manual setup required. |
| Server upgrade | When Simple Application Server no longer meets your requirements, share a custom image to ECS and use it to create ECS instances or replace the OS of existing instances. ECS offers a broader range of instance types for production workloads. For details, see Overview of instance families and instance type selection best practices. |
Migrate to ECS in three steps
If you are ready to move your workload to ECS, follow these steps:
Create a custom image from your Simple Application Server.
Create an ECS instance from the shared image, or replace the OS of an existing instance.
What's next
| Operation | Description | Reference |
|---|---|---|
| Create a custom image | Back up your server's disk as a custom image, which you can then share to ECS or use to create servers with the same configuration. | Create a custom image |
| Share a custom image | Share a custom image with ECS to transfer your workload from Simple Application Server to ECS. | Share an image to ECS |
| Unshare a custom image | Revoke ECS access to a custom image. Unshare before deleting. | Unshare images with ECS |
| Copy a custom image | Copy a custom image to another region. | Copy a custom image |
| Delete a custom image | Delete images you no longer need to free up your image library. | Delete a custom image |
| Use a custom image to create servers | Create Simple Application Servers with a pre-configured environment from a custom image. | Use a custom image to create simple application servers |