Migrate ECS instances on CloudBox hosts and DDHs in a CloudBox

Scenarios

You can migrate an ECS instance in the following scenarios.

• Uneven resource allocation: Some hosts are under heavy load while others are idle. You can migrate instances to balance the load across hosts and improve resource utilization.

• Performance improvement: The current host does not support the instance types that your business requires, which results in poor performance. You can migrate the ECS instance to a host that supports higher-specification instance types to improve performance and processing speed.

• Disaster recovery: If a host fails, you can migrate its ECS instances to a healthy host to ensure business continuity.

Prerequisites

• You have purchased a CloudBox. The target CloudBox host or DDH must have sufficient available compute resources, such as CPU and memory, and Elastic Block Storage resources for the instance migration.

• Only offline migration is supported. Before you start, make sure that the ECS instance to be migrated is in the Stopped state. For more information, see Stop an instance.

  Important

  Stopping an instance interrupts your business. Proceed with caution.

• The ECS instance to be migrated must use the pay-as-you-go billing method.

• The target DDH must meet the following conditions:

  • It shares a CloudBox with the ECS instance to be migrated.

  • If the source DDH that hosts the ECS instance is of a custom type, the instance can be migrated only to another DDH of a custom type. For more information, see Instance types.

Migrate an ECS instance from a CloudBox host to a DDH

1. Log on to the ECS console.

2. In the left-side navigation pane, choose Instances & Images > CloudBox.

3. In the top navigation bar, select a region.

4. Click the Cloud Boxes tab.

5. Find the cloud box that you want to manage and go to the details page of the cloud box by using one of the following methods:

   • In the Cloud Box ID/Name column, click the ID of the cloud box.

   • Click Details in the Actions column.

6. Click the Basic Information > Compute Resources tab. In the ECS Instance Distribution section, find the ECS instance that you want to migrate and click Adjust Host in the Actions column.

7. In the Adjust Host Deployment dialog box, configure the parameters.

   The following table describes the parameters.

   Configuration Item	Description
   Target Host	From the list of target DDHs, select the DDH within the CloudBox to which you want to migrate the ECS instance. Note If your account has no DDHs that meet the migration requirements, the target DDH list is empty.
   Target Instance Type	You can change the instance configuration during migration. The supported instance configurations depend on the specifications of the target DDH. Custom type: For the target instance type, you can slide the pointer to adjust the number of vCPUs and the memory size. The minimum adjustment unit for vCPUs is 1 vCPU. For more than 1 vCPU, only even numbers are supported, such as 2 vCPUs and 4 vCPUs. The minimum adjustment unit for memory is 1 GiB. Other DDH types: The target instance type list displays the instance types that support configuration changes.
   Host Association	Select whether to permanently deploy the ECS instance on the target DDH. Yes: Permanently deploy the instance on the target DDH. After the ECS instance is stopped and its resources are released, it must be started on this DDH. If the DDH has insufficient resources, the instance fails to start. No: Do not permanently deploy the instance on the target DDH. After the ECS instance is stopped and its resources are released, it is preferentially started on this DDH. If the DDH has insufficient resources, the system automatically selects another DDH that allows automatic deployment for the instance.
   Migration Method	Only Offline Migration is supported. This requires the ECS instance to be in the Stopped state.

8. Click OK.

   Refresh the Instance List page. Check whether the Host section displays the ID and name of the target DDH.

Migrate an ECS instance between DDHs in a CloudBox

You can perform the migration from the Instances page or the Dedicated Hosts page. For more information, see Migrate an ECS instance between DDHs.

Migrate an ECS instance from a DDH to a CloudBox host

You can perform the migration from the Instances page or the Dedicated Hosts page. For more information, see Migrate an ECS instance from a DDH to a shared host.