Create a cross-zone migration job - Server Migration Center

Server Migration Center (SMC) allows you to migrate Elastic Compute Service (ECS) instances across zones in a region and change the types of the ECS instances at the same time.

Prerequisites

Note

The cross-zone migration feature is commercialized, but the instance type change feature is available only to specific users. If you want to try the instance type change feature, submit a ticket. Your account will be added to the whitelist.

The information about one or more migration sources is imported. You can import the information about a migration source by using one of the following methods:
The instances are not preemptible instances and use the subscription or pay-as-you-go billing method.
The instance families to which the instances belong support instance type changes. For information about instance families that do not support instance type changes, see the Limits section of this topic.
Snapshots are created for the disks of the instances. For more information, see Create a snapshot for a disk.
The instances reside in virtual private clouds (VPCs). If you want to change the instance type of an ECS instance that resides in the classic network, you must migrate the instance from the classic network to a VPC. For more information, see Migrate ECS instances from the classic network to a VPC.
Applications deployed on the instances do not rely on the current private IP addresses of the instances. If you select a new vSwitch when you change the instance type of an instance across zones, the system assigns a new private IP address to the instance.
The following items are not configured for the instances: IPv6 addresses, high-availability virtual IP addresses (HAVIPs), elastic network interfaces (ENIs), reverse proxies, and route tables. Alibaba Cloud Global Accelerator is disabled for the instances.

Scenarios

The available instance types of ECS instances in the current zone cannot meet your business requirements. You want to change the instance types of the instances to a specific instance type in a different zone within the same region.
You want to migrate ECS instances to a different zone within the same region as your business requirements change.

Billing

Feature

Billing rule

Across-zone server migration

Migration of servers across zones is free of charge.

Across-zone instance type change

You are charged for changing instance types across zones based on the following billing rules:

If you downgrade the instance type of a subscription instance, the instance type downgrade may result in a refund. The refundable amount is calculated based on the following formula: Refundable amount = Remaining amount of the configuration price before the downgrade - Price of the new configurations.
If you upgrade the instance type of a subscription instance, you must pay for the price difference between the original instance type and the new instance type for the remainder of the current billing cycle. Actual fees are displayed in the console.
If you change the instance type of a pay-as-you-go instance, you are charged based on the new instance type.

Limits

The following instance families do not support cross-zone instance type changes:
- Heterogeneous computing instance families
- ECS Bare Metal Instance families
- Super Computing Cluster (SCC) instance families
- Instance families based on the x86 architecture:
  - Big data instance families
  - Instance families with local SSDs
  - Security-enhanced instance families
For more information about instance families, see Overview of instance families.
If you want to change the instance type of an instance to a new instance type, the new instance type must belong to the same instance family as the original one.

Usage notes

If security software such as Safedog, Huweishen, or Yunsuo is installed on the ECS instances whose instance types you want to change, disable the software before you change instance types across zones. Otherwise, virtualization drivers may fail to be installed and the instances cannot be started. You can enable the software after you change the instance types across zones.
Make sure that the system disks of the ECS instances have more than 500 MiB of available space. Otherwise, virtualization drivers may fail to be installed and the instances cannot be started.
During cross-zone instance type changes, do not stop, restart, or release the ECS instances manually or by using O&M scripts.
You can refund an instance up to three times. An instance type downgrade may result in a refund, which consumes the refund quota.

Migration impacts

Item	Description
Amount of time required to migrate an instance	It takes about 15 minutes from when the instance is stopped until when it is migrated and started. Note After the computing and network resources of the instance are migrated, the instance is started. After the instance is started, the system continues to migrate disk data of the instance. Typically, it takes about 4 hours to migrate 100 GiB of disk data. During the migration, the I/O performance of disks degrades and snapshot- and disk-related features are not supported.
Instance state	During migration, the instance is stopped and then started again. We recommend that you schedule to migrate your instance during off-peak hours.
Software authorization code	After an instance is migrated, its software authorization codes may change.
IP address	The public IP address of the instance remains unchanged. The private IP address of the instance may change. After the instance is migrated, the new vSwitch assigns a new private IP address to the instance. You can modify the private IP address. For more information, see Modify the private IP address of an instance.
Fee	If you do not change the instance type of an instance, you are not be charged. If you change the instance type of an instance, the following fee-related changes may occur: If you upgrade the instance type of a subscription instance, you must pay for the price difference between the original instance type and the new instance type for the remainder of the current billing cycle. Actual fees are displayed in the ECS console. If you downgrade the instance type of a subscription instance, the instance type downgrade may result in a refund. The following formula is used to calculate the refund amount: Refund amount = Remaining amount of the configuration price before the downgrade - Price of the new configurations. If you change the instance type of a pay-as-you go instance, you are charged based on the new instance type.
Other	After an instance is migrated, the following attributes of the instance remain unchanged: the instance ID, public IP address, elastic IP address (EIP), media access control (MAC) address, security groups, disk serial numbers, disk IDs, username, and logon password. If an ECS instance has been added to the vServer group of a Server Load Balancer (SLB) instance before the ECS instance is migrated, the instance is not automatically associated with the SLB instance after the instance is migrated. You must manually add the instance to the vServer group of the SLB instance. For more information, see Create a vServer group.

Procedure

Log on to the SMC console.
In the left-side navigation pane, click Migration Sources.
On the Migration Sources page, click Import Migration source.
On the ECS Instance tab, find the migration source for which you want to create a migration job and click Create Migration Job in the Actions column.
If you want to change the instance types of multiple instances at a time, select the source ECS instances and click Create Migration Job below the migration source list.

In the Create Migration Job dialog box, configure the parameters.

The following table describes the parameters.

Parameter	Description
Migration Job Type	The type of the migration job. Select Cross-zone Migration.
Billing Method	If you change the instance type of only one instance, the current billing method of the instance is displayed by default. Example: Subscription. If you change the instance types of multiple instances at a time, select Subscription or Pay-as-you-go based on your business requirements. Important This parameter takes effect for all the selected instances at a time only if the current billing methods of the instances are the same.
Region	If you change the instance type of only one instance, the current region in which the instance resides is displayed by default. Example: China (Hangzhou). If you change the instance types of multiple instances at a time, select a region based on your business requirements. Important This parameter takes effect for all the selected instances at a time only if the instances reside in the same region.
Configuration-changed Instances to Be Migrated	By default, the source ECS instances are displayed.

Click Next.

In the Change Instance Type Across Zones dialog box, configure the parameters.

The following table describes the parameters.

Parameter	Description
Migration Job Type	The type of the migration job. By default, ECS Instance Migration is displayed.
Region	The current region of the instances. By default, the region in which the ECS instances reside is displayed. Example: China (Hangzhou).
Preferred Destination Zone	The zone to which you want to migrate the instances.
Preferred Network Settings	The destination vSwitch. After the instances are migrated, new private IP addresses that belong to the CIDR block of the vSwitch are randomly assigned to the instances. Important After the instance types of the instances are changed across zones, the original private IP addresses of the instances cannot be retained. Make sure that no applications deployed on the instances rely on the original private IP addresses.
Instance Type	Specify whether to change the instance types based on your business requirements. Use Current Instance Type: Do not change the instance types. Change Instance Type: Change the instance types. Only specific instance families support instance type changes. For more information, see Instance families that support instance type changes. Important You can change an instance type only into another type within the same instance family.
Preferred New Instance Type	The destination instance type. Note This parameter is displayed only if you select Change Instance Type as Instance Type.
Configuration-changed Instances to Be Migrated	Specify whether to preview the information about the instances, such as the instance IDs or names, zones, current type, VPC, destination zone, destination type, and destination vSwitch. Note You can reselect the destination zone and destination vSwitch. If you select Change Instance Type as Instance Type, you can also reselect the destination instance type.
Notes	Select ECS Terms of Service and I have backed up data.

Click OK. In the dialog box that appears, click Pay to complete the payment as prompted.
Note
When you migrate servers across zones, the value of the Estimated Cost parameter indicates the estimated fees for the instances after migration.
Return to the SMC console to view the cross-zone migration progress.
1. Log on to the SMC console.
2. In the left-side navigation pane, click Migration Jobs.
3. Click the Cross-zone Migration tab and view the migration progress in the Status column.
  The change of instance types takes a period of time.
  - If the state of the migration job changes to Completed, the cross-zone migration is complete.
  - If the state of the migration job changes to InError, the cross-zone migration failed. You can click View Logs in the Actions column to troubleshoot issues and rerun the migration job.