Step 2: Create and start a migration task

After you import the information of a migration source, Server Migration Center (SMC) automatically generates a record for the migration source. You must create and start a migration task for the migration source in the SMC console. This topic describes how to create and start a migration task.

1. Log on to the SMC console.
2. Create a migration task.
   1. In the left-side navigation pane, click Migration Sources.
   2. Find the migration source that you want to migrate.
      You can obtain the ID of the target migration source from the SMC client, as shown in the following figure. Then, you can use the ID to find the target migration source in the SMC console. For more information, see the "How do I find a migration source in the SMC console?" section in SMC FAQ.
   3. Click Create Migration Task in the Actions column.
   4. In the Create Migration Task pane, read migration instructions and configure migration task parameters.

      The Basic configuration section includes the following parameters:

      • Target Region: required. The ID of the destination region. For more information about Alibaba Cloud regions, seeRegions and zones.
      • Task name: the name of the migration task.
        Note The task name must be unique in the destination region.
      • Description: the description of the migration task.
      • Target Disk Size (GiB): the disk configuration of the destination server.

        The following table describes the parameters.

        Parameter	Required	Description
        Enable Block Replication	No	Selected: Block replication ensures a stable data transmission rate during migration. This also ensures that the source and destination disks use the same partitioning scheme. You cannot modify the size of each partition in the destination disk. When you enable block replication, the Whether to enable block replication switch appears next to Partition <N>. Cleared: SMC uses the default method to migrate the migration source. You can modify the size of each partition in the destination disk.
        System Disk	Yes	System Disk: the system disk size of the destination ECS instance. Unit: GiB. Valid values: 20 to 500. The size of the destination system disk must be greater than that of data in the source system disk. For example, if the total size of the source system disk is 500 GiB but the size of data stored in this disk is only 100 GiB, you must set this parameter to a value greater than 100 GiB. 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. Partition <N>: SMC generates a partitioning scheme for the destination system disk based on that of the source system disk. Unit: GiB. Valid values: 0 to 98. N indicates the serial number of the partition. For example, if the system disk of the migration source has only one partition, Partition 0 is generated. Whether to enable block replication: This switch is available only when you select Enable Block Replication. SMC allows or disallows you to turn on the switch based on whether the migration source supports block replication. If the migration source does not support block replication for partitions, you are disallowed to turn on this switch. If the migration source supports block replication for partitions, you are allowed to turn on this switch to migrate disk data at the partition level.
        Data Disk <N>	No	Data Disk <N>: the data disk size of the destination ECS instance. Unit: GiB. Valid values: 20 to 32768. If you select the Data Disk <N> check box, a destination data disk is generated. N indicates the serial number of the data disk. The size of the destination data disk must be greater than that of existing data in the source data disk. For example, if the total size of the source data disk is 500 GiB but the size of data stored in the disk is only 100 GiB, you must set this parameter to a value greater than 100 GiB. Partition <N>: SMC generates a partitioning scheme for the destination data disk based on that of the source data disk. Unit: GiB. Valid values: 0 to 141. N indicates the serial number of the partition. For example, if a data disk of the migration source has only one partition, Partition 0 is generated. Whether to enable block replication: This switch is available only when you select Enable Block Replication. SMC allows or disallows you to turn on the switch based on whether the migration source supports block replication. If the migration source does not support block replication for partitions, you are disallowed to turn on this switch. If the migration source supports block replication for partitions, you are allowed to turn on this switch to migrate disk data at the partition level. Note Data Disk <N> is available only if the migration source has a data disk. For more information, see Why are no data disk parameters displayed in the Create Migration Task pane? How can I resolve this issue?

      • Target Image Type: the type of the destination image. Valid values:
        • ECS Image. The following table describes the parameters.

          Parameter	Required	Description
          Image Name	No	Specifies the name of the destination ECS image generated by SMC for the migration source. Note The image name must be unique in the destination region.
          Automatic incremental synchronization	No	Specifies whether SMC automatically synchronizes incremental data of the migration source to Alibaba Cloud. To enable this feature, you must configure the following parameters: Synchronization Interval: the interval at which SMC automatically synchronizes incremental data to Alibaba Cloud Maximum mirror retention: the maximum number of images that can be retained during incremental migration SMC automatically synchronizes incremental data to Alibaba Cloud at the specified interval. For more information about best practices for incremental migration, see Migrate incremental data from a source server. If you disable this feature, incremental data is not synchronized.

        • Container Image. The following table describes the parameters.
          Note SMC does not allow you to migrate Windows servers to Container Registry. For more information, see Migrate source servers to Container Registry.

          Parameter	Required	Description
          Namespace	Yes	The namespace of the destination container image
          Repository Name	Yes	The name of the repository that stores the destination container image
          Version	No	The version of the destination container image
          RAM Role	Yes	The instance RAM role that is attached to the intermediate instance

      • Method to Run: specifies whether to run a task immediately after it is created and whether to automatically run the task.
        • Run Now: The migration task runs immediately after it is created.
        • Run Later: The migration task automatically runs at the specified time after it is created.
          Note The earliest time that you can specify to run a migration task is 10 minutes after its creation.
        • Create Only: After the task is created, you must manually start the task.

        Default value: Run Now.

      Tag and Network (Optional):

      • Migration Task Tag: the tags that you specify for the migration task. Each tag contains a key and a value. You can use tags to query and manage migration tasks.
        Note You can specify a maximum of 20 tags for a migration task.
      • Network Type: the type of the network that is used to migrate data to an intermediate instance. During migration, SMC creates an intermediate instance that connects to a VSwitch in a virtual private cloud (VPC). When you select Public Network, a public IP address is assigned to the intermediate instance.

        The following table describes the valid values.

        Parameter value	Description
        Public Network	SMC migrates data to the intermediate instance over the Internet. If you select Public Network, make sure that the migration source can access the Internet. You can choose whether to specify a VPC and a VSwitch based on your requirements. If you specify a VPC and a VSwitch, SMC creates an intermediate instance that connects to the specified VPC and VSwitch. When you migrate multiple migration sources at a time, you can specify the same VPC and VSwitch for migration tasks. This improves the usage of VPC resources. You can migrate a maximum of 100 migration sources at a time. If you do not specify a VPC or a VSwitch, SMC automatically creates a VPC and a VSwitch and creates an intermediate instance that connects to the VPC and the VSwitch. If you do not specify a VPC or a VSwitch before you migrate multiple migration sources at a time, SMC creates a VPC for each intermediate instance. Note Each Alibaba Cloud account can have a maximum of 10 VPCs in a region, including the VPCs that you create and the VPCs that are automatically created by SMC. Therefore, you can migrate a maximum of 10 migration sources at a time. To increase the VPC quota, submit a ticket.
        VPC	SMC migrates data to the intermediate instance through a VPC. If you select VPC, you must specify a VPC and a VSwitch and make sure that the migration source can connect to the VPC. Note If your server in the on-premises data center, virtual machine, or cloud host can connect to a VPC, we recommend that you select this mode to migrate data. Compared with data migration over the Internet, VPC-based data migration is more efficient and stable. You can use VPN Gateway, Express Connect, and Smart Access Gateway to connect a migration source to a VPC. For more information, see Connect an on-premises data center to a VPC network.

      Advanced Settings (Optional):

      • Transmission speed limit (KB/S): the maximum bandwidth for data transmission during migration. Unit: Kbit/s.

        The default value is 0, which indicates that the bandwidth is not limited.

      • Compression Level: the compression ratio of data to be migrated. Set the compression ratio based on your requirements.
        • If the bandwidth is limited, a high compression ratio improves the transmission efficiency.
        • If a high bandwidth is available, we recommend that you do not compress data. Data compression consumes CPU resources of the migration source.

        The default value is 0, which indicates that data to be migrated is not compressed.

      • Checksum: This feature enhances the verification of data consistency between the migration source and the destination server, but may compromise the data transmission rate.

        By default, this feature is disabled.

   5. After the configuration is complete, click OK.
3. Start the migration task.
   Note If you set the Method to Run parameter to Run Now, skip this step. If you set the Method to Run parameter to Create Only or Run Later, you can perform the following steps to start the migration task.
   1. In the left-side navigation pane, click Migration Tasks.
   2. Find the target migration task and click Start in the Actions column.
      • To start multiple migration tasks at a time, select the target tasks and click Start/Retry in the lower part of the Migration Tasks page. The status of the selected tasks must be Ready, Stopped, or Error.
      • To suspend a migration task in the Syncing state, click Pause in the Actions column.