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    Server Migration Center:Migrate servers to ECS

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    Server Migration Center:Migrate servers to ECS

    Last Updated:Mar 26, 2026

    Server Migration Center (SMC) securely and efficiently migrates servers to Alibaba Cloud ECS from various sources, including on-premises data centers, virtual machines (VMs) such as VMware, VirtualBox, Xen, KVM, and Hyper-V, and other cloud providers such as Amazon Web Services (AWS), Microsoft Azure, Google Cloud Platform (GCP), Tencent Cloud, UCloud, China Telecom Cloud, and QingCloud. SMC simplifies the migration process and significantly reduces the technical challenges and risks of server migration.

    Migration scenarios

    Important

    Due to a change in the underlying migration technology, Server Migration Center (SMC) will no longer support migrating Windows servers to destination instances in Alibaba Cloud regions outside the Chinese mainland after November 30, 2025 (UTC+8). Before this date, you can still use SMC client V2.8.5 and earlier. For more information about the change and its impact, see [Product Change] SMC Will No Longer Support Migrating Windows Servers to Destination Instances in Alibaba Cloud Regions Outside the Chinese mainland.

    • (Recommended) Migrate a server to a custom image

      If you do not have an ECS instance, you can migrate your server to a custom image. You can then use this custom image to manually create an ECS instance.

    • Migrate a server to an existing ECS instance

      If you have purchased an Alibaba Cloud ECS instance and its configurations, such as storage and operating system, are compatible with the source server, you can migrate the source server to that ECS instance.

      Warning

      After migration, the original data on the destination ECS instance will be erased. The data on the source server is not affected. Therefore, do not use this method if the destination ECS instance contains important data.

    Migration impact

    Before you migrate, review the following considerations.

    Impact

    Description

    Data directory migration

    During migration, SMC automatically creates a destination disk partition structure that matches the source server's structure as closely as possible. You can adjust the partition structure of the destination disk, including partition size, order, transfer method, and LVM configurations.

    By default, SMC migrates all disks on the server. Note the following:

    • If a data disk has no mount target, SMC does not migrate it.

    • If you do not need to migrate specific partition directories, you can exclude them when you adjust the partition structure.

    Intermediate instance

    Do not interfere with the intermediate instance.

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

    Note

    • For each migration, SMC creates a temporary pay-as-you-go intermediate instance named No_Delete_SMC_Transition_Instance in your destination Alibaba Cloud account for the migration.

    • If you choose to migrate to a destination instance, that instance serves as the intermediate instance, and SMC does not automatically release it.

    For more information, see How SMC works.

    IP address

    The IP address changes after migration, which may cause service interruptions. Perform the migration during off-peak hours. If your services involve IP address configurations, you must modify the domain name resolution, ICP filing, and other related information after the migration.

    Underlying hardware

    After migration, the underlying hardware of the server changes. This can invalidate application licenses that are bound to specific hardware. Verify your licenses after migration.

    Performance impact

    The migration process consumes server resources, including CPU, memory, disk I/O, and network bandwidth.

    Data consistency before and after migration

    For information about data and system configuration changes that can occur during migration, see Data consistency issues after migration.

    Impact on web applications and related services

    Migrating a server to an ECS instance changes several aspects of your environment. These include network topology, compute and storage resources, security settings, costs, monitoring, compatibility, network latency, bandwidth, and backup and recovery processes.

    Impact

    Description

    Network connectivity

    After the migration, the ECS instance uses a new VPC. This changes its network location and other configurations. The instance cannot directly communicate with your original network or other ECS instances in different VPCs. To enable cross-account and cross-VPC communication, see VPC interconnection.

    Security group

    After the migration, the ECS instance uses new security group rules to control inbound and outbound traffic. Changes to access rules may affect your services. If the security group in the destination account does not have the required rules, you can export rules from the source security group and import them into the destination security group. For more information, see Import and export security group rules.

    SSL certificate

    If your website uses HTTPS, you must apply for and install an SSL certificate. You can apply for a free SSL certificate from Alibaba Cloud and deploy it to the 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 an ECS instance.

    Other configurations

    Ensure that database connections, APIs, SLB, and other settings point to the new domain name and ECS IP address.

    Prerequisites

    • Complete the pre-migration preparations.

    • Review the migration guide to learn about the SMC client, how migration works, billing, the migration process, and feedback channels.

    • To prevent data loss, back up important data to an image, a snapshot, or a storage device separate from the instance before migration.

    • If you need to migrate servers across international regions, the migration speed may be slow due to public network instability. Please evaluate the migration time and test the transfer speed. We recommend that you use a service such as VPN Gateway, Express Connect, an Express Connect circuit, or Smart Access Gateway to connect the source server and an Alibaba Cloud VPC and migrate your servers over a private network.

    • If you can directly access a VPC in an Alibaba Cloud region from your on-premises data center, virtual machine environment, or cloud host, use the SMC private network migration solution. This method is faster and more stable than migrating over the public network.

    • If you plan to migrate a source server to an existing ECS instance, ensure that the following requirements are met:

      • If the source server runs Linux, the destination instance must also run a Linux distribution. If the source server runs Windows, the destination instance must also run Windows.

      • The number of data disks attached to the destination instance must be greater than or equal to the number of data disks on the source server. If the destination instance does not have enough data disks, you must attach data disks.

      • We recommend that the capacity of the system disk and data disks on the destination instance be greater than or equal to the capacity of the corresponding disks on the source server. If you plan to reduce the disk size during migration, the capacity of the disks on the destination instance must be greater than or equal to the used space of the corresponding disks on the source server. If the disk capacity of the destination instance is insufficient, you must resize the disks.

    Migration procedure

    Step 1: Import a migration source

    A migration source is a physical server, VM, or cloud server from an on-premises data center (IDC) or another cloud platform.

    Import with the CLI

    Important

    • The source server must have public network access. If the source server is protected by a firewall, see SMC endpoints to obtain the required SMC endpoints and ports, and add them to the firewall allowlist.

    • If your source server cannot access the public network or you want to improve migration efficiency by using a private network, see Private network-based migration.

    1. Go to the SMC console - Server Migration page.

    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)

      This parameter applies to batch migrations to ECS images. You can skip this parameter for single-server migrations.

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

      If no workgroup is created, click Create a New Workgroup.

      Migration Source Type

      Physical server/VM/cloud server from other cloud platforms

      Import Method

      Select Import with command line.

      An activation code script is generated on demand. You can run the script on the source server to import the migration source with a single command.

      Migration Source Quota

      The number of migration sources that can be activated by using the activation code. Valid values: 1 to 1,000. Default value: 200.

      Validity Period

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

      Activation Code

      After you generate the activation code, copy the command. Follow these steps:

      1. Click Generate.

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

      3. Click Copy to copy the activation code command.

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

        image.png

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

      Windows source server

      1. Log on to the Windows source server.

      2. Open Windows PowerShell as an administrator.

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

        image.png

        A message similar to Import Source Server [s-bp19rlidl3mwuptc****] Successfully! indicates that the migration source has been imported successfully.

        If the command fails, see What do I do if the command fails when I import a Windows-based migration source from the command line?.

    5. In the SMC console, go to the Server Migration page and view the status of the migration source in the Migration Status column.

      • If the status is Online, the migration source is successfully imported.

      • If another status is displayed, the import failed. Troubleshoot the issue and import the migration source again.

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

          • Windows source server: C:\smc

          • Linux source server: /smc

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

    Import with the SMC client

    Important

    • The SMC client must be running on the source server. By default, public network access is enabled. If the source server is protected by a firewall, see SMC endpoints to obtain the required SMC endpoints and ports, and add them to the firewall allowlist.

    • If your source server cannot access the public network or you want to improve migration efficiency by using a private network, see Private network-based migration.

    1. Go to the SMC console - Server Migration page.

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

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

      Parameter

      Description

      Migration source type

      Physical server/VM/cloud server from other cloud platforms

      Import method

      Select Import with client.

      You must manually download and install the SMC client on the source server.

      Import instructions

      1. In the Import instructions section, download, install, and activate the appropriate SMC client based on the operating system (Linux or Windows) and architecture (32-bit or 64-bit) of the source server.

      2. Click Generate activation code and copy the activation code.

        You must enter the activation code when you install the client.

    4. Import the migration source.

      Important

      Do not close the SMC client during the migration. Otherwise, the migration source will lose its connection to the SMC console, causing the migration to fail.

      Windows source server

      1. Use a remote connection tool that supports file transfer, such as WinSCP, to upload the SMC client to the Windows source server.

      2. On the Windows source server, use a built-in or third-party decompression tool to extract the SMC client package.

      3. In the SMC client folder that corresponds to your source server's system version, double-click go2aliyun_client.exe.

        When prompted for administrator privileges, click OK.

      4. Obtain an activation code or an AccessKey.

        • (Recommended) Obtain an activation code: In the Import instructions section in the SMC console, click Generate activation code and copy the activation code.

        • Obtain an AccessKey: An Alibaba Cloud AccessKey consists of an AccessKey ID and an AccessKey secret. If you do not have an AccessKey, create one first. For more information, see Create an AccessKey pair.

      5. As prompted, enter the values for access_access_token_id and access_token_code, and press Enter.

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

      Linux source server

      1. Use a remote connection tool that supports file transfer, such as WinSCP, to upload the SMC client to the Linux source server. Alternatively, use the commands provided in the import instructions to download the SMC client on the source server.

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

        This example uses the Linux 64-bit General-purpose Edition. If you use a different version of the SMC client, replace the package name in the command with the name of the file that you downloaded.

        tar -zxvf go2aliyun_client.tar.gz
        Note

        The Linux 64-bit ARM Edition supports the g6r general-purpose and c6r compute-optimized instance families. For more information about instance types, see Enterprise-level Arm-based compute instance families.

      3. (Optional) You can exclude specific files or directories from the migration.

        Important

        If you enable block replication, you cannot exclude files or directories.

      4. Obtain an activation code or an AccessKey.

        • (Recommended) Obtain an activation code: In the Import instructions section in the SMC console, click Generate activation code and copy the activation code.

        • Obtain an AccessKey: An Alibaba Cloud AccessKey consists of an AccessKey ID and an AccessKey secret. If you do not have an AccessKey, create one first. For more information, see Create an AccessKey pair.

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

        This example uses the go2aliyun_client2.6.5_linux_x86_64 directory. The directory name varies based on the client version. Make sure to replace it with the name of the folder that you decompressed.
        cd go2aliyun_client2.6.5_linux_x86_64
sudo chmod +x go2aliyun_client
sudo ./go2aliyun_client

      6. Enter the activation code or AccessKey as prompted. This example uses an activation code:adad

        After you enter the activation code or AccessKey, the following prompts may appear:

        • If a snapshot driver is not installed on the source system, the SMC client prompts you to install one, as shown in the following figure. You can choose whether to install it.

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

          • If you do not enable block replication when you create the migration task, enter no.

          Important

          If the snapshot driver fails to install, do not enable block replication when you create the migration task. Otherwise, the migration fails.

          123

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

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

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

        Note

        If the migration source fails to import, troubleshoot the issue based on the returned message. Then, run the following commands in sequence to exit the background process 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. In the SMC console, go to the Server Migration page and view the status of the migration source in the Migration Status column.

      • If the status is Online, the migration source is successfully imported.

      • If another status is displayed, the import failed. Troubleshoot the issue and import the migration source again.

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

          • Windows source server: C:\smc

          • Linux source server: /smc

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

    Step 2: Configure migration task

    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 basic parameters.

        Parameter

        Description

        Destination Type (Required)

        Select a destination type based on your migration scenario:

        ECS Image

        Convert the source server into a custom image. You can use the custom image to create ECS instances.

        The following table describes the parameters.

        • Destination region: The region to which you want to migrate the source server. This parameter is required. For more information about regions, see Regions and zones.

        • Image name prefix: The prefix of the destination custom image name that SMC generates for the migration source.

        ECS Instance

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

        Important

        When you migrate a source server to a destination instance, the operating system of the destination instance is first replaced. The automatic snapshots of the system disk are cleared and cannot be recovered. If you want to retain the automatic snapshots for data security or future use, you can configure the automatic snapshots not to be released with the cloud disk before the migration. For more information, see Configure automatic snapshots to be released with disks.

        The following table describes the parameters.

        • Destination region: The region to which you want to migrate the source server. This parameter is required. For more information about regions, see Regions and zones.

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

        Migration Test

        The Migration Test feature helps you evaluate the feasibility and risks of a migration task before the actual migration. It provides key information, such as data volume, migration speed, and total duration. It also offers suggestions to resolve potential issues, which helps reduce problems and losses during the actual migration. Pay-as-you-go resources used during a Migration Test incur fees. By default, Migration Test is enabled.

        Warning

        If Destination type is set to ECS Instance, snapshots are created for all cloud disks of the destination ECS instance during the Migration Test. If an issue occurs during the test or if Execution method is set to Test Only, the snapshots are automatically rolled back after the test is complete. The destination ECS instance is unavailable during the Migration Test, and any pre-existing data on the instance will be overwritten. Therefore, ensure the destination ECS instance does not contain important data.

        For more information, see Configure a Migration Test.

        Execution method

        Select an execution method based on whether Migration Test is enabled.

        With migration test

        • Test only: Creates a Migration Test task only. After the test is complete, you must manually start the server migration task.

        • Test and migrate: After the Migration Test is complete, the system automatically starts the server migration task if no test items have a status of Critical. By default, Test and migrate is selected.

        Without migration test

        • Migrate now: Starts the migration immediately after you create the migration task. By default, Migrate now is selected.

        • Schedule migration: The migration task automatically starts at the specified time.

          Note

          The earliest scheduled time is 10 minutes after the current time.

        • Create only: Creates the migration task only. You must later start the migration task by clicking Start migration job in the Actions column.

        Auto incremental sync

        Enable this feature to automatically synchronize incremental data from the source server to Alibaba Cloud. By default, this feature is disabled.

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

          • Sync interval: The interval at which the incremental migration task is automatically and periodically run.

          • Max images to keep: The maximum number of images that are retained by default for an incremental migration task.

          The migration task is periodically run to synchronize incremental data to Alibaba Cloud. For more information about best practices for incremental migration, see Incremental server migration.

        • If you disable this feature, the migration task runs only once.

        Use migration template

        This parameter is available only when Destination type is set to ECS Image.

        Migration templates are used to preset migration task parameters. When you start a migration, the template parameters are automatically populated. For more information about how to set up a migration template, see Set up a migration template.

        Network mode

        Select the network used to transfer migration data to the intermediate instance. By default, data is transferred over the public network. An intermediate instance is created in the selected VPC and vSwitch and is assigned a public IP address.

        Public network

        Migration data is transferred to the intermediate instance over the public network. To use this mode, the source server must have public network access. You can choose whether to specify a VPC and a vSwitch.

        • Specify a VPC and a vSwitch: The migration task creates an intermediate instance in the VPC and vSwitch that you specify.

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

        Private network

        Migration data is transferred to the intermediate instance over the VPC's internal network. To use this mode, you must connect the source server to the Alibaba Cloud VPC and specify a VPC and vSwitch.

        Note

        We recommend that you use this method if you can directly access a VPC in an Alibaba Cloud region from your on-premises data center (IDC), VM environment, or cloud host. Data transfer over a private network is faster and more stable than over the public network, which improves migration efficiency. You can connect the source server to the VPC by using VPN Gateway, Express Connect, or Smart Access Gateway. For more information, see Connect a VPC to a data center or another cloud.

        Destination instance IPv4 private address

        If you want to change the private IP address of the destination instance, you can manually specify a private IP address. This parameter is available only when Destination type is set to ECS Instance.

        • Keep unchanged: By default, the private IP address of the Destination Instance remains unchanged.

        • Manually specify: You can enter an IP address from the available IP range of the vSwitch where the Destination Instance resides. If the IP address of the migration source is within the CIDR block of the vSwitch, you can change the IP address of the destination instance to the IP address of the migration source.

          • If the destination instance and the migration source are in the same CIDR block: Enter the private IP address of the migration source.

          • If the destination instance and the migration source are in different CIDR blocks: You must first change the VPC of the destination instance so that they are in the same CIDR block. Then, enter the private IP address of the migration source.

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

        Parameter

        Description

        Adjust disk partition structure

        Specifies whether to adjust the disk partition structure. This feature is supported only by SMC client V2.8.0 and later. For more information about the SMC client, see SMC client user guide.

        • Disabled: The disk information of the source instance is not displayed. The system automatically reads the source instance disk information to generate a disk structure. After migration, the destination disk partition structure matches the automatically generated structure by default.

        • Enabled: The disk information of the source instance is displayed, and the system automatically reads it to generate a disk structure. You can adjust the destination disk partition structure, including partition size and order, transfer method, and whether to enable LVM.

          The following table describes the disk partition parameters.

          Configure disks

          • System disk: The size of the system disk for the destination ECS instance, in GiB. Valid values: 20 to 2,048.

            The size of the destination system disk must be greater than the used space of the source system disk. For example, if the source system disk is 400 GiB in size and 100 GiB of space is used, the destination system disk must be larger than 100 GiB.

            Note

            The default value is the size of the source system disk. If you do not need to reduce the system disk size, we recommend that you do not set this parameter to a value smaller than the default value.

          • Data disk <N>: The size of the data disk for the destination ECS instance after migration, in GiB. Valid values: 1 to 32,768.

            • The variable <N> indicates the data disk number. If you migrate the source server to a destination instance, N is the data disk ID.

            • The size of the destination data disk must be greater than the used space of the source data disk. For example, if the source data disk is 500 GiB in size and 100 GiB of space is used, the destination data disk must be larger than 100 GiB.

            • A data disk is not migrated if it has no mount points or if all of its mount points are set to not be migrated.

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

            You can enable LVM based on your requirements. If you enable LVM, the destination disk is automatically rebuilt with an LVM structure.

            Example:

            For each destination disk with LVM enabled, the system creates one physical volume (PV) and its corresponding volume group (VG). In this VG, it creates a number of logical volumes (LVs) corresponding to the number of mount points. The VG name defaults to vgX (where X is the disk number), and the logical volume name defaults to lvX (where X is the logical volume number), as shown in the following figure:

            image

            Important

            LVM is not supported in the following scenarios:

            • The migration source runs a Windows operating system.

            • The system disk does not have a boot partition.

            After LVM is enabled, 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 runs a Debian system with a kernel version of 3.x or earlier and has a disk with an XFS file system mounted.

          Configure mount points

          • Migrate: Choose whether to migrate the mount point based on your business requirements.

          • Enable block replication: This parameter is visible only for SMC client versions earlier than 3.2.0. Using block replication can improve the stability of migration transfer speed and ensure consistency with the source partition structure, but the partition size cannot be modified. SMC determines whether block replication is supported based on the status of the source server disk partitions.

            • If the migration source does not support block replication for a partition, this option cannot be enabled. File replication is used by default, and the partition size can be modified.

            • If the migration source supports block replication for a partition, this option is enabled by default to perform partition-level disk migration.

            Note

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

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

          • Set partition size: If block replication is disabled, you can set the partition size, but the sum of partition sizes cannot exceed the total disk size.

            • Windows operating system: You cannot adjust the partition size.

            • Linux operating system: You can set the partition size as needed, but the sum of the partition sizes cannot exceed the size of the disk it belongs to.

              For SMC client versions earlier than 3.2.0, you must make sure that block replication is disabled.
          Note

          If the disk sizes of the destination instance and migration source do not match, the task cannot be created. In this case, the system automatically adjusts the mount point locations to meet the disk size requirements. If the requirements are still not met after the adjustment, resolve the issue as prompted on the page.

          You can also manually drag mount points to meet disk size requirements. However, you cannot drag boot or system partitions. Perform the following steps:

          1. Hover the pointer over the image icon in front of the mount point.

          2. Drag the mount point to another disk.

      3. (Conditionally required) To set parameters such as the network mode, private IP address, and transfer rate limit, click Advanced Settings. The following table describes the advanced parameters.

        Parameter

        Description

        Migration job name

        The name of the migration task.

        Migration job description

        The description of the migration task.

        Rate limit

        The maximum data transfer rate, in Mbit/s. If Compression ratio is set to a value greater than 0, the actual network transfer rate of compressed data is lower than the rate displayed in the Migration Status column.

        Compression ratio

        The level of data compression during migration. Set the compression ratio based on your business requirements.

        • In environments with limited bandwidth, a high compression ratio can increase the data transfer rate.

        • In environments with high bandwidth, we recommend that you do not compress data to reduce CPU consumption on the source server.

        Valid values: 0 to 10. Default value: 7. A value of 0 indicates that data is not compressed during transfer.

        Checksum verification

        Enabling this feature enhances data consistency verification but may reduce the transfer rate.

        SSL encryption

        By default, this parameter is set to Auto. Using SSL to encrypt migration data can improve data security and ensure data integrity.

        License type

        Select a license type.

        • Alibaba Cloud (Default): Currently, only Microsoft Windows Server licenses are provided. After migration, license fees apply when you create an ECS instance from the resulting image in the China (Hong Kong) region or regions outside the Chinese mainland. The instance is activated automatically. The specific fee is displayed at the time of instance creation.

        • BYOL: Bring Your Own License (BYOL) is supported for operating systems such as Microsoft Windows, Red Hat Enterprise Linux, and SUSE Linux Enterprise Server. After migration, no license fee is charged when you create an ECS instance from the image. You must activate the instance by using your own license.

          Note

          If you have an existing ECS instance, you can purchase software licenses such as Red Hat Enterprise Linux and SUSE Linux Enterprise Server for the instance. For more information, see Purchase a software license for an ECS instance.

        Image check

        The image check feature verifies whether an image is valid and can be used to create a fully functional ECS instance. You can use this feature when you create a server migration task or a VMware agentless migration task.

        Image check helps you quickly identify potential issues with the image or instance after migration and provides solutions to ensure compliance with Alibaba Cloud standards and improve the instance startup success rate.

        For more information, see Configure an image check.

        Tag

        Add key-value tags to the migration task to facilitate search and management. For more information, see Use tags to manage migration sources and tasks and Implement fine-grained access control by using tags.

        Note

        You can add a maximum of 20 tags to a migration task.

        Intermediate instance type

        Select an instance type for the intermediate instance based on your requirements. This parameter is available only when Destination type is set to ECS Image.

        • If you specify this parameter, the system uses the selected instance type to create the intermediate instance. If the specified instance type is out of stock, the migration task fails to be created.

        • If you do not select an intermediate instance type, the system selects an instance type in a predefined order to create the intermediate instance.

        Important

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

        Upload diagnostic logs

        Automatically upload SMC client logs to the SMC server for diagnostic analysis. This helps troubleshoot issues when a migration error occurs. This feature is enabled by default.

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

    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 enabled Migration Test, SMC performs the test first. The data transfer duration depends on factors such as data volume and network bandwidth. Wait for the migration task to complete.

      image

      Note

      • Speed: The transfer rate of migration data, measured based on the data size before compression. If you set the Compression ratio to a value greater than 0, the displayed speed is higher than the actual network transfer rate of the compressed data.

      • Time Remaining: Calculated as (Total Data - Transferred Data) / Speed.

      • If the transfer rate is too slow for your plan, you can temporarily increase the fixed bandwidth of the source and destination servers. For more information, see Estimate the migration duration and test the transfer rate.

      Subscribe to migration error notifications, and modify or pause a migration

      • To prevent the migration process from being blocked by task errors, you can subscribe to SMC migration task error event notifications in CloudMonitor to receive timely email alerts.

      • While a migration task is in the Synchronizing state, you can also perform the following operations on the task:

        • Modify a migration task: In the Actions column, click Modify migration job to change parameters such as the rate limit, compression ratio, and checksum verification.

        • Pause a migration task: In the Actions column, click Pause migration job to pause the migration.

    5. (Optional) View migration details.

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

    Verify the migration result

    • The migration is successful when the Real-time Migration Status is Completed.

      • If you set Destination Type to ECS image:

        A successful migration creates an Alibaba Cloud custom image. To view the image detection results, scroll to the right and click View Report in the Migration Deliverables column. For more information, see View image detection results.

        image

        Manual verification (recommended)

        In the Actions column, click Create Instance. You are redirected to the instance creation page in the ECS console, where the new custom image is preselected. For more information about how to create an ECS instance, see Create an instance from a custom image or shared image.

        image

        Automatic verification

        Note

        To use this feature, the instance must have the Cloud Assistant agent installed and run a supported operating system. For more information, see Install the Cloud Assistant agent.

        This feature uses the OOS template ACS-SMC-CreateAndVerifyInstance provided by Alibaba Cloud to automatically verify that an ECS instance can be created and started from the image generated by the migration task.

        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 configure the verification parameters.

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

          • Verified: The migration passed verification. You can click Details to view the results.

          • Not Verified: The migration failed verification. You can click View Cause to view the error details and troubleshoot the issue.

          To view the OOS template's execution history, click the ... icon in the Actions column and then click View Verification Records in OOS Console.

      • If you set Destination Type to ECS instance, click View Destination Instance in the Actions column to view the destination instance.

      After you migrate the server, perform the following steps to ensure that your services run as expected:

    • If the migration drill status is image.png, the migration drill has failed.

      You must review the drill report, resolve all Critical items, and then retry the migration drill. For more information, see Configure a migration drill.

    • If the Real-time Migration Status is Error, the migration task has failed.

      In this case, troubleshoot the issue and then retry the migration:

      1. In the Actions column, click Troubleshoot Errors. Resolve the issue based on the error code and message. For more information, see SMC FAQ and Troubleshoot errors.

      2. After resolving the issue, click Retry Migration in the Actions column. The migration resumes from where it left off.

        Important

        If the intermediate instance has been released, you must restart the migration. For more information, see What do I do if I accidentally release an intermediate instance?.

    Clean up resources

    ECS image migration

    During the migration, SMC creates a temporary pay-as-you-go intermediate instance named No_Delete_SMC_Transition_Instance in your destination Alibaba Cloud account to facilitate the migration. You may need to manually release the instance based on the migration outcome:

    • Successful migration: The intermediate instance is automatically released. No manual action is required.

    • Migration error: The intermediate instance is retained and continues to incur charges. To avoid unnecessary charges, you can release it in one of the following ways:

      • If you no longer need the migration task, click the migration source ID. In the Actions column, click Cancel Migration. This action deletes the task and automatically releases the intermediate instance.

      • Manually release the intermediate instance.

    ECS instance migration

    During the migration, SMC creates and attaches a temporary pay-as-you-go intermediate disk named SMC_Temp_Disk to the destination instance to facilitate the migration. You may need to manually release this intermediate disk based on the migration outcome:

    • Successful migration: The intermediate disk is automatically released. No manual action is required.

    • Migration error: The intermediate disk is retained and continues to incur charges. To avoid unnecessary charges, you can release it in one of the following ways:

      • If you no longer need the migration task, click the migration source ID. In the Actions column, click Cancel Migration. This action deletes the task and automatically releases the intermediate disk.

      • Manually release the intermediate disk.

    Related documents

    • After the initial full migration completes, you can run multiple incremental migrations at custom intervals to synchronize incremental data from the source server to Alibaba Cloud. This process reduces business downtime and the final cutover time. For more information, see Incremental server migration.

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