Resources are the actual entities that you use when you use Elastic Compute Service (ECS). Each create operation may generate corresponding resources, such as ECS instances, auto provisioning groups, custom images, disks, security groups, and elastic network interfaces (ENIs).


  • Before you use a RAM user to create and manage resources, you must have the RAM user granted corresponding permissions by your Alibaba Cloud account. For more information, see Control access to resources by using RAM users.
  • The number of resources that can be created and retained depends on your ECS usage. For more information, see Limits.

Resource IDs

Each resource has a resource ID. The resource ID serves as a unique identifier of the resource and makes your search and management of the resource easier. A resource ID consists of the first letter of the English word of the resource, a hyphen (-), and a string of a fixed length. Examples: instance ID i-bp13izg0l4s3********, custom image ID m-bp1gbwvlscsk********, and launch template ID lt-bp18i1ibppnr********.

In code or CLI operations, the values of some parameters must be resource IDs. For example, the following command can be run to start an ECS instance whose ID is i-bp13izg0l4s3********:
aliyun ecs StartInstance --InstanceId i-bp13izg0l4s3********

Resource locations

The following table describes the limits on the regions and zones in which ECS resources reside. For more information, see Regions and zones.
Resource Location Description
Instance Zone An ECS instance is tied to the zone in which it is created. Within the same region, the availability of instance types varies based on zones.
Reserved instance Zone or region
  • Zonal reserved instances provide zone-level resource reservation capabilities.
  • Regional reserved instances can be used to offset the pay-as-you-go bills of specific instance types within the same region.
Image Region
  • Custom image: You can bypass the region limits on custom images by replicating the custom images. You can replicate a custom image from one region to another and generate a custom image with a new ID within the destination region. For more information, see Copy custom images.
  • Public image: When a public image is released in all regions, no region limits apply to the image.
Elastic Block Storage (EBS) device Zone An EBS device can be attached only to ECS instances within the same zone.
Storage capacity unit (SCU) Region An SCU can be used to offset the pay-as-you-go bills of disks within the same region.
Snapshot Region A snapshot can be used to back up data of the corresponding disk within the same region.
Security group Region If you do not configure a cloud service for communication over the Internet, you cannot enable ECS instances within security groups in different regions to communicate over the internal network by adding security group rules.
SSH key pair Region You can bypass the region limits by importing SSH key pairs. You can use a tool to create an SSH key pair and import it to the region in which you want to use it. For more information, see Import an SSH key pair.
Instance RAM role Region An instance RAM role can be assigned only to ECS instances within the same region.
ENI Region An ENI can be bound only to ECS instances within the same region.
Launch template Region A launch template is tied to its region. You must specify the zone where to use the launch template to create ECS instances.
Deployment set Region ECS instances within the same region can be added to the same deployment set.
Auto provisioning group Region An auto provisioning group is tied to its region. You must specify the zone where the auto provisioning group creates pay-as-you-go or preemptible instances.
Tag Region A tag can be added only to ECS instances within the same region.
Cloud Assistant command Region A Cloud Assistant command can be run only on ECS instances within the same region.