All Products
Search

This Product

    Server Migration Center:Migrate a server to an ECS instance

    Document Center

    Server Migration Center:Migrate a server to an ECS instance

    Last Updated:Jun 14, 2025

    Server Migration Center (SMC) allows you to migrate servers from self-managed data centers, on-premises VMs (VMware, VirtualBox, Xen, KVM, Hyper-V), or third-party cloud providers (Amazon AWS, Microsoft Azure, Google GCP, Tencent Cloud, UCloud, China Telecom Cloud, QingCloud) to Alibaba Cloud ECS securely and efficiently. SMC simplifies the migration process and significantly reduces the technical complexity and risks of server migration.

    Migration scenarios

    Important

    Due to changes in server migration transit technology, after November 30, 2025 (UTC+8), Server Migration Center (SMC) will no longer support migrating Windows servers to Alibaba Cloud regions outside the Chinese mainland. Before this date, SMC client version 2.8.5 and earlier versions will still support this functionality. For more information about the changes and impacts, see [Product Change] Announcement: SMC no longer supports migrating Windows servers to Alibaba Cloud regions outside the Chinese mainland.

    • (Recommended) Migrate a server to an ECS custom image

      If you have not purchased an Alibaba Cloud ECS instance, you can migrate a server to an ECS custom image and then manually use the custom image to create an ECS instance.

    • Migrate a server to an existing Alibaba Cloud ECS instance

      If you have purchased an Alibaba Cloud ECS instance and the configurations of the ECS instance such as storage and operating system match those of the source server, you can migrate the source server to the purchased ECS instance.

      Warning

      After the migration, the original data in the destination ECS instance is cleared (the data on the source server is not affected). Therefore, if the destination ECS instance contains important data, we recommend that you do not use this method for migration.

    Impacts

    Before migration, take note of the information in the following table.

    Item

    Description

    Data directory

    During migration, SMC can automatically generate a disk partition structure that is as consistent as possible with that of the source server based on the disk partition structure of the source server. You can adjust the partition structure of the destination disk as needed, including the partition size and location sequence, transfer mode, and whether to enable LVM.

    By default, all disks of the server are migrated, but the following conditions still need to be considered:

    • If no mount targets exist under the data disk, the data disk is not migrated.

    • If you do not need to migrate some partition directories, you can choose not to migrate them when adjusting the disk partition structure.

    For more information, see Adjust the disk partition structure as needed.

    Intermediate instance

    Do not interfere with the intermediate instance.

    To prevent migration failures, do not stop, start, restart, or release the intermediate instance or change the billing method of the intermediate instance during the migration process. After the migration is complete, the intermediate instance is automatically released.

    Note

    • During each migration, SMC creates a pay-as-you-go temporary intermediate instance named No_Delete_SMC_Transition_Instance in your Alibaba Cloud destination account (for the default instance type range, see What specifications are available for intermediate instances?) to assist with the migration.

    • If you choose to migrate to a destination instance, the destination instance serves as the intermediate instance and will not be automatically released.

    For more information, see How it works.

    IP address

    After migration, the IP address will change, which may cause service interruption. We recommend that you perform the migration during off-peak hours. If your business involves IP address configuration, you need to modify domain name resolution, ICP filing, and other settings after migration.

    Underlying hardware

    After migration, the underlying hardware will change, which may cause certain hardware-bound application licenses to become invalid. Please perform necessary checks.

    Peripheral impact on web applications after server migration

    After a server is migrated to Alibaba Cloud ECS, the business network topology, computing and storage resources, application security settings, cost, monitoring, compatibility, network latency and bandwidth, backup and recovery, and O&M processes will change. You also need to pay attention to the following aspects:

    Item

    Description

    Network connectivity

    After server migration, the ECS instance will use a new virtual private cloud (VPC), and its network location and other configurations will change with the migration of the VPC. This ECS instance cannot directly communicate with other ECS instances in the original network or VPC. If you need to implement cross-account and cross-VPC communication, see VPC peering.

    Security group

    After server migration, the ECS instance will use new security group rules to control inbound and outbound traffic. Changes in access rules may affect normal business access. If the destination account's security group does not have the corresponding security group rules, you can quickly add security group rules by exporting the security group rules associated with the original ECS instance and importing them to the destination security group. For more information, see Import and export security group rules.

    SSL Certificate

    If your website uses HTTPS services, you need to apply for and install an SSL certificate. You can apply for a free SSL certificate through Alibaba Cloud and deploy it to your ECS instance. For more information, see Purchase and deploy an SSL certificate to an ECS instance.

    Data migration

    If you need to migrate data from other servers to Alibaba Cloud, you can use methods such as FTP, SCP, or manual backup to OSS. For more information, see Transfer files to an ECS instance and Use ossutil to transfer data to ECS.

    Other configurations

    Database connections, APIs, Server Load Balancer (SLB), etc. Ensure they point to the new domain name and ECS IP address.

    Prerequisites

    • You have completed the preparations for server migration. For more information, see Before you begin.

    • You understand the SMC client, migration principles, migration billing, migration process, feedback channels, etc. For more information, see Migration guide.

    • To avoid data loss, we recommend that you back up important data to images, snapshots, or storage devices other than the instance.

    • If you need to migrate servers across international regions, the migration speed may be slow due to unstable public network environments. For more information, see Estimate the time required for migration and test the data transfer speed. We recommend that you connect the source server to an Alibaba Cloud VPC through VPN Gateway, Express Connect, physical connection, or Smart Access Gateway, and migrate through a private network. For more information, see Connect a data center to a VPC.

    • If you can directly access an Alibaba Cloud VPC in a specific region from your self-managed data center, VM environment, or cloud host, we recommend that you use SMC's private network transmission migration solution. Migration through SMC's private network is faster and more stable than through the public network, improving migration efficiency. For more information, see Migrate servers over a VPC.

    • If you need to migrate a source server to a purchased Alibaba Cloud ECS instance:

      • You need to back up all important data on the instance to images, snapshots, or devices other than the instance.

      • If the source server runs a Linux system, the destination instance must be a Linux distribution; if the source server runs a Windows system, the destination instance must be a Windows system.

      • The number of data disks attached to the destination instance must be greater than or equal to the number of data disks on the migration source. If the number of data disks on the destination instance does not meet the requirements, you need to attach more data disks. For more information about attaching data disks, see Attach a data disk.

      • The capacity of the system disk and data disks of the destination instance should be greater than or equal to the capacity of the system disk and data disks of the migration source. If you need to shrink the system disk and data disks of the source server, the capacity of the system disk and data disks of the destination instance must be at least equal to the actual used capacity of the system disk and data disks of the source server. If the cloud disk capacity of the destination instance does not meet the requirements, you need to resize the cloud disks. For more information about resizing cloud disks, see Cloud disk resizing guide.

    Migration procedure

    Step 1: Import the migration source

    A migration source refers to the server you want to migrate, such as an IDC server, a virtual machine, a cloud host from another cloud platform, or other types of servers. SMC supports multiple methods to import migration sources. You can choose the appropriate method based on your actual needs. For more information, see How do I choose a method to import migration sources?.

    (Recommended) Import migration source using command line

    Important

    • The source server must have public network access capability. If the source server has firewall restrictions, see What are the service domains of SMC? to obtain SMC domains and ports, and add them to the firewall whitelist.

    • If your source server cannot access the public network or you want to improve migration efficiency through private network transmission, please use the SMC client import method.

    1. Visit SMC console - Server Migration.

    2. On the Server Migration page, click Import Migration source.

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

      Parameter

      Description

      Workgroup (optional)

      Applicable to batch migration to ECS image scenarios. For single server migration, please skip this parameter.

      You can add multiple migration sources to the same workgroup for management. Migration sources associated with a workgroup must enable automatic incremental synchronization during migration. For more information about batch server migration, see Batch migration of servers.

      If no workgroup has been created, click Create a New Workgroup.

      Migration Source Type

      Select Physical Server/VM/Cloud Servers Of Other Cloud Platforms.

      Import Method

      Select Use CLI To Import Server: Generate an activation code script command as needed, and execute it on the source server to import the migration source with one click.

      Migration Source Quota

      Enter the number of migration sources that can be activated with the activation code. Valid values: 1 to 1000. Default value: 200.

      Validity Period

      Enter the validity period of the activation code. Valid values: 1 to 90 days. Default value: 90 days.

      Activation Code

      After generating the activation code, copy the command. The steps are as follows:

      1. Click Generate.

      2. Based on the source server operating system, click the Linux Shell or Windows Powershell tab.

      3. Click Copy to copy the activation code command.

    4. Log on to the source server, paste and run the copied command with administrator privileges to import the migration source.

      Linux source server

      1. Log on to the Linux source server.

      2. Paste and run the copied command with administrator privileges to import the migration source.

        image.png

        After executing the command, if a message similar to Import Source Server [s-bp18x8751kgz2oyh****] Successfully! appears, it indicates that the migration source has been successfully imported.

      Windows source server

      1. Log on to the Windows source server.

      2. Open Windows PowerShell with administrator privileges.

      3. Paste and run the copied command to import the migration source.

        image.png

        After executing the command, if a message similar to Import Source Server [s-bp19rlidl3mwuptc****] Successfully! appears, it indicates that the migration source has been successfully imported.

        If the command execution fails, see What do I do if the command fails to be run when I import the information of a Windows migration source by using the CLI?.

    5. On the Server Migration page in the SMC console, check the status of the migration source in the Real-time Migration Status column.

      • If the migration source status is Migration Source Online, the migration source has been successfully imported.

      • If the migration source has another status, the import has failed. Please refer to the following solutions to resolve the issue, then re-import the migration source.

        • Troubleshoot the issue based on the error message displayed in the console or by checking the log files in the SMC client directory. The default installation directories for the SMC client are as follows:

          • Windows source server: C:\smc.

          • Linux source server: /smc.

        • For common issues and solutions, see SMC FAQ and Troubleshooting.

    Import migration source through the console

    Important

    • Only supports importing Alibaba Cloud ECS servers.

    • The source server must be in the Running state and Cloud Assistant must be in normal available status. For more information, see View Cloud Assistant status and handle abnormal states.

    • If you use a RAM user to import migration sources, you need to grant the following permissions to the RAM user:

      • Grant the RAM user read-only access to Elastic Compute Service (ECS) with the permission AliyunECSReadOnlyAccess. For more information, see Grant permissions to a RAM user.

      • Grant the RAM user Cloud Assistant management permission AliyunECSAssistantFullAccess. For more information, see Grant permissions to a RAM user.

    1. Visit SMC console - Server Migration.

    2. On the Server Migration page, click Import Migration source.

    3. Configure the relevant parameters based on the migration source type.

      Parameter

      Description

      Workgroup (optional)

      Applicable to batch migration to ECS image scenarios. For single server migration, please skip this parameter.

      You can add multiple migration sources to the same workgroup for management. Migration sources associated with a workgroup must enable automatic incremental synchronization during migration. For more information about batch server migration, see Batch migration of servers.

      If no workgroup has been created, click Create a New Workgroup.

      Migration Source Type

      Select ECS Instance.

      Import Method

      Select Import Through Console: Authorize Server Migration Center to remotely connect to the source server from the console to automatically import the migration source. The import process will automatically call the Cloud Assistant feature. Do not interrupt or exit the process.

      Region

      Select the region where the server to be migrated is located from the dropdown list.

      Instance

      Select the Alibaba Cloud ECS instance to be migrated in the specified region. You can also select multiple Alibaba Cloud ECS instances to batch import migration sources.

      You can search for the ECS instance to be migrated by instance ID/name and IP address.

      Tag (optional)

      Bind tag key-value pairs to the migration task for easier querying and management. For more information, see Use tags to manage migration sources and migration tasks and Use tags to implement fine-grained access control.

      Note

      A single migration task can be bound to a maximum of 20 tags.

      Resource Group (optional)

      If you need to group and manage migration resources based on business departments, projects, or other dimensions, you can create resource groups to achieve this.

    4. After configuring the parameters, click Import.

      SMC will automatically start Cloud Assistant to perform the import. Importing a migration source takes approximately 3-10 minutes. Please wait patiently.

    5. On the Server Migration page in the SMC console, check the status of the migration source in the Real-time Migration Status column.

      • If the migration source status is Migration Source Online, the migration source has been successfully imported.

      • If the migration source has another status, the import has failed. Please refer to the following solutions to resolve the issue, then re-import the migration source.

        • Troubleshoot the issue based on the error message displayed in the console or by checking the log files in the SMC client directory. The default installation directories for the SMC client are as follows:

          • Windows source server: C:\smc.

          • Linux source server: /smc.

        • For common issues and solutions, see SMC FAQ and Troubleshooting.

    Import migration source through the SMC client

    For more information about the SMC client, see SMC client user guide.

    Important

    • Client import requires the source server to run the client, with public network access mode enabled by default. If the source server has firewall restrictions, see What are the service domains of SMC? to obtain SMC domains and ports, and add them to the firewall whitelist.

    • If your source server cannot access the public network or you want to improve migration efficiency through private network transmission, please refer to Migrate servers over a VPC to set up private network transmission.

    1. Visit SMC console - Server Migration.

    2. On the Server Migration page, click Import Migration source.

    3. On the Import Migration Source page, configure the relevant parameters as described in the following table.

      Parameter

      Description

      Migration Source Type

      Select Physical Server/VM/Cloud Servers Of Other Cloud Platforms.

      Import Method

      Select Use Client To Import Server: Manually download and install the SMC client on the source server.

      Description

      In the Description section, follow the instructions to download, install, and activate the appropriate SMC client based on the source server's operating system (Linux and Windows) and architecture (32-bit and 64-bit).

      Click Generate and copy the activation code information. You will need to enter this activation code when installing the client.

    4. Import the migration source.

      Choose the appropriate operation based on the source server's operating system:

      Important

      During the migration process, do not close the SMC client until the migration is complete. Otherwise, the migration source will lose connection with the SMC console, and the migration will fail.

      Import migration source from Windows source server

      1. Use a third-party remote connection tool that supports file transfer to upload the SMC client to the Windows source server. For example: WinSCP.

      2. On the Windows source server, use Windows' built-in extraction tool or your own extraction tool to decompress the SMC client package.

      3. In the SMC client folder that matches your migration source system version, run the SMC client.

        • GUI version: Double-click to run the go2aliyun_gui.exe application.

        • Command line version: Double-click to run the go2aliyun_client.exe application.

        Note

        When running the program, you will be prompted for administrator privileges. Click OK.

      4. Obtain an activation code or an AccessKey.

        • (Recommended) Obtain an activation code: In the Description section of the SMC console, click Generate and copy the activation code information.

        • Obtain an AccessKey: An Alibaba Cloud account's AccessKey includes an AccessKey ID and an AccessKey Secret. If you haven't created one, create it first. For more information, see Create an AccessKey.

      5. Follow the prompts to enter the activation code or AccessKey.

        • GUI version: In the Token Id/AK and Token Code/SK text boxes, enter the activation code or AccessKey, then click Run. For more information, see SMC client user guide.

        • Command line version: Enter the activation code values for access_access_token_id and access_token_code, and press the Enter key.

        When a message similar to Import Source Server [s-bp18x8751kgz2oyh****] Successfully! appears, it indicates that the migration source has been successfully imported.

      Import migration source from Linux source server

      1. Use a third-party remote connection tool that supports file transfer to upload the SMC client package to the Linux source server. For example: WinSCP.

      2. Remotely connect to the Linux source server and decompress the SMC client package.

        This example uses the decompression of Linux 64-bit Generic. If you are using another version of the SMC client, replace the package name in the command with the actual name of the downloaded SMC client.

        tar -zxvf go2aliyun_client.tar.gz
        Note

        Linux ARM64 supports the g6r general-purpose instance family and the c6r compute-optimized instance family. For more information about instance specifications, see Enterprise-level ARM computing instance families.

      3. (Optional) If you do not need to migrate certain files or directories, you can exclude them from migration. For more information, see How do I filter or exclude files or directories that do not need to be migrated?.

        Important

        If you enable the block replication feature, you cannot exclude files or directories from migration.

      4. Obtain an activation code or an AccessKey.

        • (Recommended) Obtain an activation code: In the Description section of the SMC console, click Generate and copy the activation code information.

        • Obtain an AccessKey: An Alibaba Cloud account's AccessKey includes an AccessKey ID and an AccessKey Secret. If you haven't created one, create it first. For more information, see Create an AccessKey.

      5. In the SMC client folder, run the following commands to start the SMC client.

        cd go2aliyun_client_linux_x86_64
sudo chmod +x go2aliyun_client
sudo ./go2aliyun_client

      6. Follow the prompts to enter the activation code or AccessKey. This example uses an activation code: adad

        After entering the activation code or AccessKey, you may see the following prompts:

        • If the migration source system does not have a snapshot driver installed, the SMC client will prompt you as shown in the following figure. You can choose whether to install the snapshot driver based on your needs.

          • If you want to enable block replication when creating a migration task, enter yes to automatically install the snapshot driver.

          • If you do not want to enable block replication when creating a migration task, enter no.

          Important

          If the snapshot driver installation fails, do not enable block replication when creating a migration task, otherwise the migration will fail.

          123

        • Most mainstream migration source systems have rsync installed by default. If it is not installed, the SMC client will prompt you to enter yes to automatically install rsync, as shown in the following figure. 安装rsync

        • If SELinux is enabled on the migration source system, the SMC client will prompt you to disable it. Enter yes to automatically disable SELinux, as shown in the following figure. 关闭SELinux

        When a message similar to Import Source Server [s-bp11npxndknsycqj****] Successfully! appears, it indicates that the migration source has been successfully imported.

        Note

        If the migration source import fails, you can troubleshoot the issue based on the returned message. After resolving the issue, run the following commands in sequence to exit the background program and re-import the migration source. For more information about common issues and solutions, see SMC FAQ and Troubleshooting.

        sudo ./go2aliyun_client --abort
sudo ./go2aliyun_client

    5. On the Server Migration page in the SMC console, check the status of the migration source in the Real-time Migration Status column.

      • If the migration source status is Migration Source Online, the migration source has been successfully imported.

      • If the migration source has another status, the import has failed. Please refer to the following solutions to resolve the issue, then re-import the migration source.

        • Troubleshoot the issue based on the error message displayed in the console or by checking the log files in the SMC client directory. The default installation directories for the SMC client are as follows:

          • Windows source server: C:\smc.

          • Linux source server: /smc.

        • For common issues and solutions, see SMC FAQ and Troubleshooting.

    Step 2: Migration configuration

    1. Find the migration source that you want to manage and click Start Migration in the Actions column.

    2. Configure the parameters and click Start Migration.

      1. Configure the basic parameters as described in the following table.

        Parameter

        Description

        Example

        Migration Job Name

        The name of the migration job.

        Server migration

        Job Description

        Enter a description for the migration job.

        test

        Destination Type (Required)

        You can select the corresponding destination type based on your actual migration scenario:

        ECS image

        Convert the existing source server into an ECS custom image, and then use this custom image to create a new ECS instance to complete the migration.

        Configuration items:

        • Destination Region: The destination region refers to the Alibaba Cloud region to which your source server will be migrated. This parameter is required. For more information about regions, see Regions and zones.

        • Image Name: The name of the destination Alibaba Cloud custom image generated by SMC for the migration source.

        ECS instance

        Migrate the source server directly to a purchased ECS instance. The storage, operating system, and other configurations of the source server and the purchased ECS instance must be compatible.

        Important

        When migrating to a destination instance, the operating system of the destination instance will be replaced first, and automatic snapshots of the system disk will be cleared and cannot be recovered. If you need to retain automatic snapshots for future needs or data security considerations, you can manually cancel the automatic snapshot release with the disk before migration. For more information, see Delete automatic snapshots while releasing a disk.

        Configuration items:

        • Destination Region: The destination region refers to the Alibaba Cloud region to which your source server will be migrated. This parameter is required. For more information about regions, see Regions and zones.

        • Destination Instance: Select an ECS instance as the destination instance.

        ECS Image

        Migration Test

        Specifies whether to enable the migration test feature. This feature helps you understand the feasibility and risks of a migration job before the migration job starts and provides solutions to identified issues. You can also obtain information such as the amount of data to be migrated, migration speed, and total duration of the migration. This helps reduce the issues and losses that may occur during the actual migration. During the test, you are charged for pay-as-you-go resources. By default, Migration Test is turned on.

        Warning

        If you set the Destination Type parameter to ECS Instance, snapshots are created for all disks of the destination ECS instance. If the migration test is abnormal or the Execution Method parameter is set to Test Only, the disk snapshots are automatically rolled back. During the migration test, the destination ECS instance is unavailable and all data is lost. Make sure that the destination ECS instance does not have important data.

        For more information, see Configure a migration test.

        Keep the default setting

        Execution Method

        Select the execution method based on whether Migration Test is enabled:

        When Migration Test is enabled

        • Test Only: This option only creates a migration test task. After the migration test is complete, if you need to migrate the server, you must manually start the server migration task.

        • Test And Migrate: This option indicates that after the migration test is complete, if there are no test items in the Critical state, the system automatically starts the server migration task. Test And Migrate is selected by default.

        When Migration Test is not enabled

        • Migrate Now: The migration starts immediately after the migration task is created. Migrate Now is selected by default.

        • Migrate Later: After the migration task is created, it automatically starts at the scheduled time.

          Note

          The earliest scheduled execution time can be set to 10 minutes after the current time.

        • Create Only: This option only creates a migration task. You need to click Start Task in the Actions column to manually start the migration task later.

        Keep the default setting

        Automatic Incremental Synchronization

        Specifies whether SMC automatically synchronizes incremental data of the migration source to Alibaba Cloud. By default, this feature is disabled.

        • If you enable this feature, you must configure the following parameters:

          • Synchronization Interval: the interval at which SMC automatically synchronizes incremental data to Alibaba Cloud.

          • Maximum Reserved Images: the maximum number of images that can be retained during incremental data synchronization.

          SMC automatically synchronizes incremental data to Alibaba Cloud at the specified interval. For more information about the best practices for incremental data synchronization, see Migrate incremental data from a server.

        • After you turn off this switch, the migration task executes only once.

        Keep the default setting

        Enable Migration Template

        This parameter appears only when Destination Type is set to ECS Image.

        The migration template is used to preset parameters for a migration task, and the template parameters are automatically filled in when the migration starts. For more information about setting up a migration template, see Configure the migration template.

        Keep the default setting

      2. Adjust the disk partition structure as needed. The following table describes the parameters.

        Parameter

        Description

        Example

        Modify Disk Partition

        Determine whether to enable Modify Disk Partition based on your needs. This feature is only supported in SMC client 2.8.0 or above. For more information, see Use the SMC client.

        • Not enabled: By default, the disk partition structure of the destination system are the same as those of the migration source.

        • Enabled: You can adjust the destination disk partition structure, including partition size and order, transfer method, whether to enable LVM, and other configurations.

          The parameter descriptions for the disk partition structure are as follows.

          Configure disks

          • System Disk: the size of the system disk of the destination instance. Unit: GiB. Valid values: 20 to 2048,

            The size of the destination system disk must be larger than the amount of data on the source system disk. For example, if the total size of the source system disk is 400 GiB but the size of data stored on this disk is only 100 GiB, you must set this parameter to a value greater than 100.

            Note

            The default value of this parameter is the size of the source system disk. We recommend that you retain the default value or specify a greater value.

          • Data Disk <N>: the size of the data disk of the destination instance. Unit: GiB. Valid values: 1 to 32768.

            • The variable <N> indicates the serial number of the data disk. If the disk is migrated to the destination instance, N is the ID of the data disk.

            • The size of the destination data disk must be larger than the amount of data on the source data disk. For example, if the total size of the source data disk is 500 GiB but the size of data stored on this disk is only 100 GiB, you must set this parameter to a value greater than 100.

            • If there are no mount targets under the Data Disk or if all mount targets are not migrated, the data disk will not be migrated.

          • LVM: Logical Volume Manager (LVM) is a mechanism for managing disk partitions in Linux systems. LVM is more flexible than traditional disk partitions and allows for dynamic adjustment of disk space.

            You can select whether to enable LVM based on your needs. After enabling LVM, the destination will automatically rebuild the disk with an LVM structure.

            Example:

            For each destination disk where LVM is enabled, the system will create one Physical Volume (PV) and its corresponding Volume Group (VG). On the VG, a number of Logical Volume Manager (LVM) corresponding to the mount targets are created. By default, the VG name is vgX (where X is the serial number of the disk), and the LVM name is lvX (where X is the serial number of the LVM). An example is provided in the following figure.

            image

            Important

            LVM is not supported in the following scenarios:

            • When the migration source is a Windows system.

            • When the system disk does not have a boot partition.

            After enabling LVM, the feature does not take effect in the following scenarios:

            • The migration source does not support lvm2 or the lvm2 package is not installed.

            • The migration source is a Debian system with a kernel version of 3.x or earlier, and disks with XFS file systems are mounted.

          Configure mount targets

          • Whether to Migrate: You can select whether to migrate the mount target based on your business needs.

          • Enable Block Replication: Enabling block replication can effectively improve the stability of migration transmission speed while ensuring consistency with the source partition structure. However, the partition size cannot be modified. SMC determines whether to support enabling block replication based on the migration source disk partition status.

            • If the migration source does not support block replication for partitions, the Enable Block Replicationswitch cannot be turned on, and default file replication method is used, allowing partition size modification.

            • If the migration source supports enabling Block Replication for partitions, block replication is enabled by default to achieve partition-level disk migration.

            Note

            • When the migration source is a Windows operating system, the block replication feature is enabled by default and cannot be disabled.

            • If LVM is enabled on the disk and the partition size is not an integer multiple of 4 MiB, block replication does not take effect, and file replication is used for data transfer.

          • Set partition size: When block replication is not enabled, you can set the partition size based on your needs, but the sum of partition sizes cannot exceed the size of the disk they belong to.

          Note

          If the size of disks of the destination instance do not match that of the migration source disks, the migration task cannot be created. In this case, the system will automatically adjust the mount target positions to meet the disk size requirements. If the requirements cannot be met after the adjustment, handle the issue as prompted.

          You can also manually drag and drop mount targets to meet disk size requirements. However, drag-and-drop is not supported for partitions of type boot or system. The specific operations are as follows:

          1. Move your pointer over image before the mount target.

          2. Use your pointer to drag the mount target to another disk.

        Keep the default setting

      3. Conditionally required. If you need to set parameters such as network mode, modify private IP address, transmission speed limit, etc., click Advanced Configuration, and configure the advanced parameters as described in the following table.

        Parameter

        Remarks

        Example

        Network Type

        Select the network used to transfer migration data to the intermediate instance. By default, data is transferred over the public network. The intermediate instance will be created under the selected virtual private cloud (VPC) and vSwitch, so a public IP address will be assigned to the intermediate instance.

        Public Network (default)

        Migration data is transferred to the intermediate instance over the public network. When using this mode, the source server must be able to access the public network. Based on your actual needs, choose whether to specify a VPC and vSwitch.

        • Specify VPC and vSwitch: The migration task creates an intermediate instance under your specified VPC and vSwitch.

        • Do not specify VPC and vSwitch: The migration task creates an intermediate instance under a VPC and vSwitch that are automatically created by the system.

        Private network

        Migration data is transferred to the intermediate instance through the VPC internal network. When using this mode, you need to connect the source server to the Alibaba Cloud VPC, and you must specify a VPC and vSwitch.

        Note

        If you can directly access a virtual private cloud (VPC) in an Alibaba Cloud region from your self-managed data center (Integrated Data Center, IDC), virtual machine environment, or cloud host, we recommend that you use this method for migration. Using internal network transmission provides faster and more stable data transfer compared to the public network, improving migration efficiency. You can connect the source server to the cloud VPC through VPN Gateway, Express Connect circuit, or Smart Access Gateway. For more information, see Connect a data center to a VPC.

        Keep the default setting

        IPv4 Private Address

        If you need to change the private IP address of the destination instance, you can manually specify the private IP address. This parameter appears only when the Destination Type is selected as ECS Instance.

        • Remain Unchanged: The default value is the IP address of the destination instance after migration and does not change.

        • Manually Specify: You are allowed to enter an address within the available IP CIDR block of the vSwitch where the destination instance is located. When the migration source IP address is in the CIDR block of the vSwitch, you can change the destination instance IP address to the migration source IP address.

          • When the CIDR block of the destination instance is the same as that of the migration source: Enter the private IP address of the migration source.

          • When the CIDR block of the destination instance is different from that of the migration source: You need to first change the VPC of the destination instance, making the CIDR block of the destination instance the same as that of the migration source, and then enter the private IP address of the migration source.

        Transmission Speed Limit

        Transmission speed limit restricts the actual network transmission speed, measured in Mbps. If the Compression Ratio is set to a value greater than 0, the actual network transmission speed (i.e., the transmission speed of compressed data) will be lower than the speed displayed in the Real-time Migration Status.

        Keep the default setting

        Compression Ratio

        The compression level for data transmission during migration. Set the compression ratio based on your actual needs.

        • In environments with limited bandwidth, using a high compression ratio can improve data transmission speed.

        • When bandwidth is high, we recommend not compressing data transmission to reduce CPU resource consumption on the migration source.

        Valid values: 0 to 10. Default value: 7. The value 0 indicates that data is not compressed.

        Keep the default setting

        Checksum Verification

        Disabled by default. When enabled, it enhances data consistency verification but may reduce transmission speed.

        Keep the default setting

        Enable SSL Encrypted Transmission

        Enabled by default. Using SSL encryption for data migration enhances data security while ensuring data integrity.

        Keep the default setting

        License Type

        The license type.

        • Alibaba Cloud (default value): Currently only Microsoft Windows Server licenses are supported. After migration, when creating ECS instances using the image in China (Hong Kong) and regions outside China, you will be charged for the image license fee, and it will be automatically activated. The specific cost is subject to the information displayed when creating the instance.

        • Bring Your Own License: Bring Your Own License (BYOL) migration to the cloud currently mainly includes Microsoft, Red Hat Enterprise Linux, and SUSE Linux Enterprise Server. When creating ECS instances using the image after migration, you will not be charged for the image license fee. Please use your own license for activation.

          Note

          If you have already created an ECS instance, Alibaba Cloud supports quickly purchasing software licenses such as Red Hat Enterprise Linux and SUSE Linux Enterprise Server for specified ECS instances. For more information, see Purchase a software license for an ECS instance (invitational preview).

        Keep the default setting

        Image Check

        The image check feature checks whether an image is valid and whether the image can be used to create full-featured Elastic Compute Service (ECS) instances. You can use the image check feature when you create server migration and VMware agentless migration tasks.

        Image check helps you quickly identify potential issues in images or instances after migration, and provides solutions to make them comply with Alibaba Cloud standards, improving the success rate of instance startup.

        For more information, see Configure image check.

        Keep the default setting

        Tag

        Bind tag key-value pairs to migration tasks for easier querying and management. For more information, see Use tags to manage migration sources and migration jobs and Use tags to implement fine-grained access control.

        Note

        You can specify up to 20 tags for a migration task.

        Keep the default setting

        Intermediate Instance Type

        You can select the intermediate instance type based on your actual needs. This parameter appears only when Destination Type is set to ECS Image.

        • Automatically Select Intermediate Instance Type: The system will select this instance type to create the intermediate instance. If the inventory of this instance type is insufficient, the migration task creation will fail.

        • If you do not specify the parameter, SMC automatically creates an intermediate instance.

        Important

        To avoid migration errors, do not stop, start, restart, or release the intermediate instance during the migration process. After the migration is complete, the instance will be automatically released.

        Keep the default setting

        Upload Diagnostic Logs

        Automatically uploads SMC client logs to the SMC server for error diagnosis and analysis, which helps locate issues when migration errors occur. This feature is enabled by default.

        SMC client logs are typically saved in the /smc/go2aliyun_client*/Logs directory under the installation folder.

        Keep the default setting

    3. In the message that appears, read the migration notes and click Got It.

    4. On the Server Migration page, view the real-time migration status.

      If you enable a migration test, SMC will first perform the migration test and proceed with the migration operation after the test passes. The amount of time required for data transmission varies based on factors such as the data size of the migration source and the network bandwidth. Wait until the migration job is complete.

      image

      Note

      • Speed: the amount of data that is migrated per second, which indicates the transfer speed of uncompressed data. If you set the Compression Ratio parameter to a value greater than 0, the displayed speed will be greater than the actual network transfer speed (which is the transfer speed of compressed data).

      • Time Remaining For Synchronization: the remaining synchronization time calculated based on the current speed by using the following formula: Time remaining for synchronization = (Total data size - Transferred data size)/Speed.

      • If the transmission speed is too small to meet your plan, you can consider temporarily increasing the fixed bandwidth of the source server and destination server. For more information, see Estimate the time required for migration and test the data transfer speed.

      Subscribe to migration error events, modify migration, and pause migration as follows:

      • Subscribe to SMC migration task error-related event notifications.

      • When the migration task status is Synchronizing, you can also perform the following operations on the migration task based on your actual needs:

        • Edit the migration job: In the Actions column, click Modify Migration Job to modify Transmission Speed Limit, Compression Ratio, Checksum Verification, and other parameters.

        • Pause the migration job: In the Actions column, click Pause Migration.

    5. (Optional) To view details about the migration, perform the following steps:

      View migration details

      In the Migration Source ID/Name column of the destination migration source, click the migration source ID to view the migration details.

      4f6e6910cfeda1780d1e406a91e2492b

    Verify the migration result

    • When Real-time Migration Status is Completed, the migration is successful.

      • If you select Destination Type as ECS Image:

        After successful migration, an Alibaba Cloud custom image is generated. You can use your mouse to slide the scrollbar at the bottom to the right and click View Report in the Migration Deliverables column to view the image detection results. For more information, see View the image check results.

        image

        Manually verify the migration result (recommended)

        You can click Create Instance in the Actions column. The system will redirect you to the ECS instance creation page in the ECS console with the created custom image selected by default. For detailed instructions on creating an ECS instance, see Create an instance by using a custom image.

        image

        Automatically verify the migration result

        Note

        To use this feature, you need to install the Cloud Assistant plugin inside the instance, and the instance system version must support it. For more information, see Install Cloud Assistant Agent.

        This feature uses the OOS template ACS-SMC-CreateAndVerifyInstance provided by Alibaba Cloud to automatically verify whether the image generated by the migration task can successfully create an ECS instance and start normally.

        1. In the Actions column, click Verify Migration Result.

          image

        2. In the dialog box that appears, review the verification process and click Verify Now.

          You can also click Customize Verification Parameters to manually configure parameters for verification.

        3. In the Verify Migration Result column, view the verification result.

          • Verification Passed: indicates that the migration result has no abnormalities. You can click Details to understand the verification result.

          • Not Verified: indicates that the migration result has anomalies. You can click View Cause to understand the reason for the migration task failure and troubleshoot the issue based on the cause.

          ...Go To OOS To View Historical Verification You can also click the icon in the Actions column and click to obtain historical execution information of the OOS template.

      • If you select Destination Type as ECS Instance, you can click View Destination Instance in the Actions column to go to the destination ECS instance page and view the destination ECS instance.

      After migrating the server, to ensure normal business operation, you need to perform the following actions:

    • If the migration test status is image.png, the migration test failed.

      You need to review the test report and fix the Critical test items before retrying the migration test. For more information, see Configure a migration test.

    • When Real-time Migration Status is Error, it indicates that the migration task has failed.

      In this case, you need to troubleshoot the issue and retry:

      1. In the Actions column, click Troubleshoot Errors, and fix issues based on the error code and error message. For more information, see SMC FAQ and Errors occurred during a server migration.

      2. After fixing the issue, click Retry Migration in the Actions column.

        The system will continue migration from where it last ended.

        Important

        If the intermediate instance has been released, you need to migrate again. For more information, see What do I do if I accidentally release an intermediate instance?.

    Clear resources

    • Migrate a server to an ECS image

      During migration, SMC creates a temporary pay-as-you-go intermediate instance named No_Delete_SMC_Transition_Instance in your Alibaba Cloud destination account to assist with migration. You need to determine whether manual cleanup is required based on whether the migration is successful:

      • If the migration is successful, the intermediate instance is automatically released. No manual operation is required.

      • If the migration failed, the intermediate instance is not automatically released and incurs fees as long as the migration job exists. You can release the intermediate instance in one of the following ways to reduce costs:

        • If you no longer need the migration job, click the migration source ID, and in the Actions column of the migration task, click Clear Migration to automatically clean up the intermediate instance by deleting the migration task.

        • Manually release the intermediate instance. For more information, see Release an instance.

    • Migrate a server to a destination instance

      During the migration, SMC creates a temporary pay-as-you-go intermediate disk named SMC_Temp_Disk in the destination instance. The method to clear resources depends on whether the migration is successful:

      • If the migration is successful, the intermediate disk is automatically released. No manual operation is required.

      • If the migration failed, the intermediate disk is not automatically released and incurs fees as long as the migration job exists. You can release the intermediate disk in one of the following ways to reduce costs:

        • If you no longer need the migration job, click the migration source ID, and in the Actions column of the migration task, click Clear Migration to automatically clean up the intermediate disk by deleting the migration task.

        • Manually release the intermediate instance. For more information, see Release a disk.

    References

    • If you need to migrate incremental data multiple times, you can initiate incremental data migration multiple times at custom intervals after the first full migration is complete. This synchronizes the incremental data generated by the source server to Alibaba Cloud and reduces the suspension time and delivery time of the services provided by the source server. For more information, see Incremental server migration.

    • For more information about frequently asked questions (FAQ) and solutions, see FAQ and Troubleshooting.