This topic provides answers to frequently asked questions about the Cloud Migration tool.

Note The Cloud Migration tool is upgraded to Server Migration Center (SMC). Alibaba Cloud no longer provides version updates and technical support to the Cloud Migration tool. We recommend that you use SMC for a better cloud migration experience. SMC provides services, which include full migration, incremental migration, batch migration, and VPC-connected migration. For more information, see Server Migration Center.

In what scenarios can I use the Cloud Migration tool?

The Cloud Migration tool can be used to migrate data from physical servers, virtual machines, and cloud servers on other cloud platforms to Alibaba Cloud ECS. The Cloud Migration tool supports migration for servers that run Windows and Linux. For more information, see Overview of the Cloud Migration tool.

What are the differences between the Cloud Migration tool and Server Migration Center (SMC)?

The Cloud Migration tool is upgraded to Server Migration Center (SMC). Alibaba Cloud no longer provides version updates and technical support to the Cloud Migration tool. We recommend that you use SMC for a better cloud migration experience. SMC provides services, which include full migration, incremental migration, batch migration, and VPC-connected migration. For more information, see Server Migration Center.

I have a single instance oriented Oracle database on a physical database server. Should I migrate the entire server (including the operating system and database) to Alibaba Cloud, or should I only migrate the database? What are the benefits and drawbacks of each migration type?

Select a migration type based on your needs. The benefits and drawbacks of each migration type are as follows:
  • If you only need a database application, we recommend that you migrate only the database to Alibaba Cloud. However, you must consider how your applications will be deployed within the new environment.
  • If you need both the database application and its operating environment, we recommend that you migrate the entire server to Alibaba Cloud. However, if the server has a large volume of resources, the migration may take an extended period of time to complete.

What is the migration process of the Cloud Migration tool?

The following figure shows the migration process of the Cloud Migration tool.
  1. Check whether the source server meets the conditions for migration.
  2. Create an intermediate instance under your Alibaba Cloud account and transfer data from the source server to the intermediate instance.
  3. Create snapshots for the intermediate instance and use the snapshots to create a custom image.

Does the Cloud Migration tool support resumable data transfer?

Yes, the Cloud Migration tool supports resumable data transfer. If data transfer is interrupted, you can re-run the Cloud Migration tool to resume migration.

Does the Cloud Migration tool support incremental migration of data?

Yes, the Cloud Migration tool supports incremental migration of data.

What happens after a migration is complete?

After the migration is complete, a custom image is generated for the source server operating system. You can log on to the ECS console and view the custom image from the list of images in the corresponding region.

What do I do after a migration is complete and a custom image has been generated?

We recommend that you create a pay-as-you-go instance from the image and ensure that the system is operating normally. After you confirm that the image functions properly, select an instance type that meets your business needs to create one or more ECS instances. For more information about instance types, see Instance families. For more information about how to create an ECS instance, see Create an instance by using the provided wizard.

What do I do if a migration is interrupted or fails?

When a migration task is interrupted or fails, you can use one of the following methods to troubleshoot the problem:
  • If the Cloud Migration tool program exits unexpectedly or freezes, you can attempt to re-run the Cloud Migration tool to resume the migration.
  • If the migration fails and the Not Finished message is returned, you can check the log file in the Logs directory to find the cause of the error and troubleshoot it. For more information about common issues and their solutions, see Troubleshooting. For more information about error codes, visit the API Error Center.

    If the problem persists, we recommend that you join the Cloud Migration tool support group on DingTalk. For more contact information, see Feedback and support.

What do I need to know about intermediate instances?

Note the following precautions for intermediate instances:
  • The Cloud Migration tool automatically creates, starts, stops, and releases the intermediate instance INSTANCE_FOR_GOTOALIYUN. To ensure a smooth migration, we recommend that you do not perform operations on the intermediate instance.
  • The default security group of the intermediate instance allows inbound access over ports 8080 and 8703. We recommend that you do not modify or delete these security group rules.
  • After the migration is complete, the intermediate instance will be released automatically. If the migration fails, you must manually release the intermediate instance. For more information about how to release the intermediate instance, see Release an instance.

What do I need to know about the user_config.json file?

If a migration has already started and the intermediate instance has already been created, we recommend that you do not modify the system disk size or data disk size specified in the user_config.json file. If you need to modify these parameters, you must clear the client_data file and restart the migration.

When do I need to filter out a file or a directory?

If the source server contains files or directories that do not need to be uploaded, you can filter out or skip these files or directories by configuring the Excludes file to improve the efficiency of migration.

In particular, you can filter out databases, Docker containers, and other active files or directories that cannot be suspended to improve the stability of data transmission during migration.

What do I need to know about the client_data file?

The client_data file records data of the migration process, including the information about the intermediate instances and the migration progress. We recommend that you do not modify or delete the client_data file. Otherwise, the migration may fail.

When do I need to clear the client_data file? How do I clear the client_data file?

You must clear the client_data file in the following circumstances:
  • If you want to restart a migration that has already been started, you can clear the existing client_data file or use the original client_data file to overwrite the existing one before you restart the migration.
  • If the migration fails due to mistaken release of intermediate instances or absence of VPCs, vSwitches, or security groups, you can attempt to resolve the migration failure by clearing the client_data file.
You can use one of the following methods to clear the client_data file:
  • Use the --cleardata CLI parameter provided by the Cloud Migration tool. For more information, see CLI parameters.
  • For Windows, use the GUI of the Cloud Migration tool for Windows. On the GUI, choose Config > Clear Client Data. For more information, see GUI of Cloud Migration tool (Windows).

How do I migrate the same source more than once?

Clear the client_data file and run the Cloud Migration tool again to migrate the migration source.

What do I do if I have released an intermediate instance by mistake?

Clear the client_data file and run the Cloud Migration tool again to migrate the migration source.

Why am I prompted with a "Forbidden.RAM" error message?

The AccessKey pair of your RAM user does not have the permissions to manage ECS or VPC resources. We recommend that you use your Alibaba Cloud account to grant permissions to the RAM user by attaching the AliyunECSFullAccess and AliyunVPCFullAccess policies to the user.

Why am I prompted with a "Forbidden.Subuser" error message?

The Cloud Migration tool must use the AccessKey pair of an account to call ECS API operations to create resources such as intermediate instances and disks. These resources must be purchased separately. Some service provider accounts may not have the permissions to create such resources. If you need to migrate resources, contact Alibaba Cloud. For more information, see Feedback and support.

To which service endpoints and ports does my server need to enable outbound access?

The source server must be able to access the following service endpoints and ports:
  • ECS: https://ecs.aliyuncs.com:443. For the endpoints of ECS in other regions, see the "Service endpoints" section in Request structure.
  • VPC: http://vpc.aliyuncs.com:443.
  • STS: https://sts.aliyuncs.com:443.
  • Intermediate instance: ports 8080 and 8703 corresponding to public IP addresses. To perform a VPC-based migration, you must access the private IP address of the intermediate instance. For more information about VPC-based migration, see Migrate services to the cloud by using Alibaba Cloud VPC.
Note You do not need to enable inbound ports for the source server. However, you must allow the server outbound access to the preceding service endpoints and ports.

After I migrate a Windows server, how do I perform checks on my system?

When you start the created instance for the first time after migrating your Windows server, you must perform the following checks:
  1. Check whether the system disk data is complete.
  2. If a data disk is missing, open the Disk Management utility to check whether the drive letter is missing.
  3. After the automatic recovery of the file system access permission is complete, choose whether to restart the instance.
    Note If the Goto Aliyun Restore Tool does not automatically start during the first startup attempt, run the C:\go2aliyun_prepare\go2aliyun_restore.exe command to manually invoke the recovery process. Before you run the command, ensure that the number of disks and drive letter paths on the instance are consistent with those of the source system.
  4. Check whether the network service is normal.
  5. Check whether other system services are operating normally.

Which Windows Server licenses does Alibaba Cloud support?

Alibaba Cloud supports licenses for Windows Server 2003, 2008, 2012, and 2016. To migrate other versions of Windows not listed here to ECS, you must apply for license mobility. For more information, see Apply for License Mobility through Software Assurance.

Before I migrate a Linux server, how do I check whether the requirements for migration are met?

You can use the client_check tool provided by the Cloud Migration tool. Run the ./client_check --check command. If all check items are displayed as OK in the command output, the requirements for migration are met.

After I migrate a Linux server, how do I perform checks on my system?

When you start the created instance for the first time after migrating your Linux server, you must perform the following checks:
  1. Check whether the system disk data is complete.
  2. If data disks exist, you must attach the data disks. For more information, see Attach a data disk.
  3. Check whether the network service is normal.
  4. Check whether other system services are operating normally.