Migrate a Windows operating system - Server Migration Center

Due to reasons such as the end of operating system maintenance (meaning EOL) or the evolution of open-source projects, when you migrate or upgrade your operating system while retaining the data on the system disk of the ECS instance, you can achieve this through SMC. This topic describes how to upgrade Windows Server 2008 R2, Windows Server 2012 R2, and Windows Server 2016 by using SMC.

Background information

Microsoft ceased support for Windows Server 2008 and Windows Server 2008 R2 operating systems on January 14, 2020, and stopped supporting Windows Server 2012 and Windows Server 2012 R2 operating systems on October 10, 2023. Alibaba Cloud no longer provides software updates and security patches for these systems. If you have ECS instances running on the aforementioned operating systems, we recommend that you take corresponding measures to continuously receive software updates and security patches to avoid the impacts of the EOL (End of Life) of the operating systems. For more information, see Windows Server EOL guidance.

Migration scenarios

The following table describes the x86-based operating systems that can be migrated by using SMC and the operating systems that can serve as migration destinations.

Migrate Windows Server 2008 R2

Operating system architecture	Source operating system	Destination operating system
x86	Windows Server 2008 R2 Standard 64-bit (Chinese/English)	Windows Server 2012 R2 Datacenter 64-bit (Chinese/English)
x86	Windows Server 2008 R2 Enterprise 64-bit (Chinese/English)	Windows Server 2012 R2 Datacenter 64-bit (Chinese/English)

Migrate Windows Server 2012 R2

Operating system architecture	Source operating system	Destination operating system
x86	Windows Server 2012 R2 Standard 64-bit (Chinese/English)	Windows Server 2016 Datacenter 64-bit (Chinese/English) Windows Server 2019 Datacenter 64-bit (Chinese/English)
x86	Windows Server 2012 R2 Datacenter 64-bit (Chinese/English)

Migrate Windows Server 2016

Operating system architecture	Source operating system	Destination operating system
x86	Windows Server 2016 Standard 64-bit (Chinese/English)	Windows Server 2019 Datacenter 64-bit (Chinese/English)
x86	Windows Server 2016 Datacenter 64-bit (Chinese/English)	Windows Server 2019 Datacenter 64-bit (Chinese/English)

Limits

Cross-language migration of Windows operating systems is not supported.
The ECS instance whose Windows operating system is to be migrated must have at least 2 vCPUs and 2 GiB of memory.
The migration tool consumes resources to download and install software packages during the migration process. Therefore, make sure that the available space of the C drive on the instance is at least 20 GiB, and the available space is larger than the size of the C:\Windows directory.

Only the following regions support Windows operating system migration.

Asia Pacific - China	Asia Pacific - Others	Europe and Americas	Middle East
China (Hangzhou) China (Shanghai) China (Qingdao) China (Beijing) China (Zhangjiakou) China (Hohhot) China (Ulanqab) China (Shenzhen) China (Heyuan) China (Guangzhou) China (Chengdu) China (Hong Kong) China (Wuhan-Local Region)	Japan (Tokyo) South Korea (Seoul) Singapore Malaysia (Kuala Lumpur) Indonesia (Jakarta) Philippines (Manila) Thailand (Bangkok)	Germany (Frankfurt) UK (London) US (Silicon Valley) US (Virginia)	UAE (Dubai)

Usage notes

Item	Description
Assess the impact of migration on your business	During the migration process, do not stop, restart, or release the ECS instance in manual mode or by using O&M scripts. Otherwise, the task may fail. If you perform a migration test or cancel a migration job, all disks of the ECS instance may be automatically rolled back to the snapshots that are created before the migration. During the migration, the operating system kernel and software packages are installed or updated and the operating system is automatically restarted multiple times. In this process, business continuity cannot be ensured. We recommend that you assess the impact of migration on your business and suspend your business before you perform a migration job.
Back up your data	During the migration process, the following operations are performed on the ECS instance: create snapshots for basic disks, switch operating system kernel versions, and reinstall, upgrade, stop, and start software packages. We recommend that you back up important data in advance and perform the migration during a proper window to prevent your business from being interrupted by the preceding operations.
Ensure no snapshots are being created	If snapshots are currently being created, it will cause the migration to fail. Wait for the snapshot creation to complete before starting the migration.
Comprehensive testing and verification	Before you migrate the operating system, we recommend that you test and verify that all your business applications are compatible with the destination operating system and run as expected in the destination operating system to ensure business continuity and functionality. Meanwhile, before and during the migration and upgrade process, the system conducts migration condition detection and pre-evaluation on the source instance. If the source system does not meet the migration conditions or the pre-evaluation fails, the migration may encounter errors and interruptions. Therefore, successful migration and upgrade cannot be guaranteed. We recommend that you familiarize yourself with migration condition limitations and troubleshooting documentation in advance and conduct tests. For migration issues, see Errors occurred during the migration of a Windows operating system.
Comprehensive testing and verification
Do not operate the intermediate Cloud disk	During the migration, the system automatically shares the snapshot of the Windows installation media with the current Alibaba Cloud account, and uses the snapshot to create and attach an intermediate disk to the instance. Do not perform operations on the intermediate disk during the migration. After the migration is complete, the intermediate disk is automatically detached and released.
Attribute of the operating system	After the operating system of an ECS instance is migrated, the original image ID of the instance remains unchanged, while the operating system is changed to the one after the migration.

Billing

During the migration, the system creates snapshots for all disks of the ECS instance to back up data. You are charged for snapshots on a pay-as-you-go basis. For more information, see Billing.

Prerequisites

The preparations for the migration are complete. For more information, see Before you begin.
The ECS instance is deployed in a virtual private cloud (VPC). If the ECS instance is in the classic network, you must migrate the ECS instance from the classic network to a VPC. For more information, see Migrate ECS instances from the classic network to a VPC.
Snapshots are created for the source operating system and data for backup, so that you can restore the source operating system and data if necessary. For more information, see Create a snapshot.
Important
If you migrate an operating system, the operating system kernel, software packages, and configurations are modified. The modifications are irreversible.

Procedure

(Recommended) Fast migration

Note

To use the SMC console to import the information about a migration source, make sure that the following conditions are met:

Internet access is enabled for the migration source.
Cloud Assistant Agent is installed on the migration source. By default, Cloud Assistant Agent is installed on ECS instances that are created based on public images after December 1, 2017.
If you want to import the information about a migration source as a Resource Access Management (RAM) user, make sure that the following permissions are granted to the RAM user:
- AliyunRAMReadOnlyAccess. For more information, see Grant permissions to a RAM user.
- The AliyunECSAssistantFullAccess policy is attached to the RAM user to grant the RAM user the permission to manage Cloud Assistant. For more information, see RAM overview.

Log on to the Server Migration Center (SMC) console.
In the left-side navigation pane, choose Cloud Migration > OS Migration.
On the OS Migration page, click Start Migration.
In the Migrate Operating System dialog box, select the ECS instance to be migrated and click Pre-check.
You can filter ECS instances by instance ID and region.
In the Migrate Operating System dialog box, the system automatically conduct pre-migration checks for the operating system, which will take approximately 10 seconds.
- When the pre-check status changes from to , it indicates that the pre-check has passed.
- When the pre-check status changes from to , it indicates that the pre-check has failed. You can follow the prompts to fix the issues and attempt the migration again.
After carefully reading the usage notes for operating system migration, select I acknowledge and accept these risks and authorize Alibaba Cloud to create snapshots for all disks on the instance and click Next.
In the pop-up Migrate Operating System dialog box, select the destination operating system as needed.
- Select the Same Destination Operating System: If you migrate the operating systems of multiple ECS instances at a time, you can select this option and specify a destination operating system for all the selected instances.
- Select Destination Operating System by Instance: If you migrate the operating systems of multiple ECS instances at a time, you can select this option and specify a destination operating system for each selected instance.
Click Check for Migratability and view the check results.
The migratability check requires approximately 30 seconds to complete.
- : You can migrate the instance to the destination operating system.
- : You cannot migrate the instance to the destination operating system. You can follow the on-screen instructions to view the reason why you cannot migrate the instance to the destination operating system.
Click Migrate.
You can view the operating system migration progress on the Migrate Operating System page.
Warning
During the migration process, do not stop, restart, or release the ECS instance in manual mode or by using O&M scripts. Otherwise, operating system migration fails.

Staged migration

Step 1: Import the information about a migration source

Migration sources can be servers of a variety of types, such as servers in data centers, VMs, and hosts on third-party cloud platforms. SMC supports multiple methods to import the information about migration sources. You can select a method based on your business requirements. For more information, see the How do I select the method to import the information about a migration source? section of the "FAQ" topic.

(Recommended) Import the information about a migration source by using the CLI

Important

The source server must be accessible over the Internet.

Log on to the Server Migration Center (SMC) console.
In the left-side navigation pane, choose Cloud Migration > OS Migration.
On the OS Migration page, click Import Migration source.

Configure the parameters as prompted and copy the activation code command. The following table describes the parameters.

Parameter	Description
Migration Source Type	Select ECS Instance.
Import Method	The method that is used to import the information about the migration source. Select Use CLI to Import Server.
Migration Source Quota	The number of migration sources whose information you want to import by using the activation code. Valid values: 1 to 1000. Default value: 10.
Validity Period	The validity period of the activation code. Unit: day. Valid values: 1 to 90. Default value: 30.
Activation Code	Generate the activation code and copy the generated command by performing the following steps: Click Generate. Click the Windows Powershell tab. Click Copy to copy the activation code command.

Import the information about the migration source.
1. Log on to the Windows server.
2. Open Windows PowerShell as an administrator.
3. Run the copied command to import the information about the migration source.
  After the command is run, if a message similar to Import Source Server [s-bp19rlidl3mwuptc****] Successfully! is returned, the information about the migration source is imported.
On the OS Migration page of the SMC console, view the status of the migration source in the Real-time Migration Status column.
- If the status of the migration source is Online, the information about the migration source is imported.
- If the migration source is in another state, the information fails to be imported. In this case, troubleshoot the failure based on the following solutions and import the information about the migration source again:
  - Troubleshoot the issue based on the message displayed in the SMC console or the log file in the directory where the SMC client is installed. By default, the SMC client is installed in the C:\smc directory.
  - Refer to the FAQ about Server Migration Center (SMC) and Troubleshooting topics for troubleshooting.

Import the information about a migration source by using the SMC client

For more information about the SMC client, see Use the Windows GUI version of an SMC client.

Log on to the Server Migration Center (SMC) console.
In the left-side navigation pane, choose Cloud Migration > OS Migration.
On the OS Migration page, click Import Migration source.

On the Import Migration Source page, configure parameters. The following table describes the parameters.

Parameter	Description
Migration Source Type	Select ECS Instance.
Import Method	The method that is used to import the information about the migration source. Select Use Client to Import Server.
Description	Read the information in the Description section and download the required version of the SMC client based on the CPU architecture (Arm or x86) and bit version (32-bit or 64-bit) of the operating system of the migration source.

Import the information about the migration source.
Important
During the migration, do not shut down the SMC client until the migration is complete. Otherwise, the migration source is disconnected from the SMC console, and the migration fails.
1. You can use a remote connection tool that supports file transfer. For example, you can use WinSCP to upload the SMC client package to the source Windows server.
2. On the source Windows server, use the built-in decompression tool of Windows or the decompression tool that you install to decompress the SMC client package.
3. In the SMC client folder that corresponds to the source server, run the SMC client.
  - To run the Windows GUI version, double-click the go2aliyun_gui.exe file.
  - To run the Windows CLI version, double-click the go2aliyun_client.exe file.
  Note
  When you run the program, you must click OK to confirm that you have the administrator permissions.
4. Obtain an activation code or AccessKey pair.
  - (Recommend) Obtain an activation code: In the Description section in the SMC console, click Generate and copy the generated activation code information.
  - Obtain an AccessKey pair: An AccessKey pair consists of an AccessKey ID and an AccessKey secret. If no AccessKey pair is created, create one first. For more information, see Obtain an AccessKey pair.
5. Enter the activation code or AccessKey pair as prompted.
  - To run the Windows GUI version, enter the activation code or AccessKey pair in the Token Id/AK and Token Code/SK fields and click Start. For more information, see Use the Windows GUI version of an SMC client.
  - To run the Windows CLI version, enter the obtained access_access_token_id and access_token_code and press the Enter key.
  If the information about the migration source is imported, a message similar to the following one is returned: Import Source Server [s-bp11npxndknsycqj****] Successfully!
On the OS Migration page of the SMC console, view the status of the migration source in the Real-time Migration Status column.
- If the status of the migration source is Online, the information about the migration source is imported.
- If the migration source is in another state, the information fails to be imported. In this case, troubleshoot the failure based on the following solutions and import the information about the migration source again:
  - Troubleshoot the issue based on the message displayed in the SMC console or the log file in the directory where the SMC client is installed. By default, the SMC client is installed in the C:\smc directory.
  - Refer to the FAQ about Server Migration Center (SMC) and Troubleshooting topics for troubleshooting.

Step 2: Create a migration job

Find the migration source that you want to manage and click Start Migration in the Actions column.
In the Migration Configuration dialog box that appears, configure the parameters.
You can configure the following parameters to create an operating system migration task:
- Current Operating System: By default, the current operating system is displayed and cannot be modified. Example: Windows Server 2008 R2 64-bit (Simplified Chinese).
- Destination Operating System: Select the operating system to which you want to migrate the source operating system from the drop-down list. In this example, Windows Server 2012 R2 Datacenter 64-bit (Simplified Chinese) is used.
In the Migrate Operating System dialog box, read the messages and click Got It.
In the Create Migration Job dialog box, click Go to the Migration Jobs page and wait until the migration job is complete.
Warning
During the migration, do not stop, restart, or release the Windows ECS instance manually or by using O&M scripts.

Verify the migration result

If the migration job enters the Completed state, the operating system is migrated.
Note
After the migration job is complete, the ECS instance automatically restarts. During the system initialization, operations such as software package updates are performed. Do not perform operations on the ECS instance until the operating system starts. The system initialization takes about 15 to 30 minutes. The actual time varies based on the number of system software packages to be processed.
On the Operating System Migration tab of the SMC console, find the migration job and click View Destination Instance in the Actions column. In the Configuration Information section of the Instance Details tab of the ECS instance, verify that the source operating system is migrated to the destination operating system.
Important
After the migration is complete, the operating system kernel and software packages of the source operating system are upgraded. Original application data is retained. However, your applications may not run as expected due to changes in the environment or dependencies. In this case, business cannot run as expected. Therefore, you must test and verify a migration solution before you perform a migration job.

If the state of the migration job changes to Error, the migration job fails.
In this case, you need to perform the following operations:
1. Click Troubleshoot Errors in the Actions column and fix the failure based on the error code and error message. For more information, see FAQ about Server Migration Center (SMC) and Troubleshooting.
2. On the Migration Jobs page, click Retry Migration Job.
  The migration job resumes from the point where it was suspended.
  Important
  If the intermediate instance is released, you must create another migration job. For more information, see the What do I do if I release an intermediate instance by accident? section of the "FAQ" topic.
If you want to roll back the system disk on which the source operating system is installed, you can use the snapshots that are automatically created for the system disk. To roll back the system disk, perform the following steps:
1. Log on to the ECS console.
2. In the left-side navigation pane, choose Storage & Snapshots > Snapshots.
3. On the Disk Snapshots tab of the Snapshots page, find the snapshot that you want to use to roll back the system disk, and click Roll Back Disk in the Actions column.
4. In the Roll Back Disk dialog box, click Confirm.

Clear resources

During the migration, SMC creates one pay-as-you-go snapshot named SMC_Backup_Snapshot_XXX for disks of the ECS instance for data backup. If you no longer need this snapshot, delete it in time to avoid unnecessary charges. For more information, see Delete a snapshot.