Incremental migration allows you to migrate incremental data from the source server to Alibaba Cloud. You can specify the time interval between incremental migration tasks. Incremental migration reduces the service interruption time and the final time of delivering services. This topic describes the best practices for incremental migration.

Prerequisites

The source server information is imported to the SMC console. For more information, see Step 1: Import the information about a migration source.
Notice Incremental migration is supported by SMC client 2.0.0 and later versions. Therefore, we recommend that you use SMC client 2.0.0 and later versions to import the migration source information.

Background information

An incremental migration task creates an intermediate instance to facilitate the migration process. The intermediate instance incurs a small amount of fees. For more information, see Pay-as-you-go. The intermediate instance is released only when the incremental migration task is in the Expired state or when the task is deleted.

Procedure

The following steps show the best practices for incremental migration:

  1. (Optional) Step 1: Exclude dynamic data directories
  2. Step 2: Create and start an incremental migration task
  3. Step 3: Stop businesses and run an incremental migration task

(Optional) Step 1: Exclude dynamic data directories

To ensure stability, we recommend that you exclude dynamic data directories, such as data directories of large databases, and migrate incremental data after the business is stopped. Skip this step if you do not need to exclude dynamic data directories from migration.

You can exclude dynamic data directories from migration without stopping businesses that run on the source server. Perform the following steps:

  1. Log on to the source server.
  2. Configure the SMC client to exclude dynamic data directories.

Step 2: Create and start an incremental migration task

You can create and start an incremental migration task in the SMC console without stopping businesses that run on the source server. Perform the following steps:

  1. Log on to the SMC console.
  2. In the left-side navigation pane, click Migration Sources.
  3. Find the source server from which you want to migrate data.
  4. Click Create Migration Task in the Actions column.
  5. In the Create Migration Task dialog box that appears, turn on the Automatic Incremental Synchronization switch, and set the Synchronization Interval and Upperlimit of Reserved Images parameters. Set other parameters based on your needs and then click OK.
    Automatic incremental synchronization

    The parameters in the preceding figure are described as follows. For more information about other parameters, see Migration task parameters.

    • Synchronization Interval: Specify the time interval between incremental migration tasks.
    • Upperlimit of Reserved Images: Specify the maximum number of reserved images. Each incremental migration task generates new images. If the total number of generated image files exceeds the upper limit, the earliest and unused images are deleted.
    • Method to Run: Select a method to run the migration task. In this topic, Run Now is selected.
    The migration task runs immediately after it is created. The result is described as follows:
    1. The first incremental migration task migrates all data except the excluded directories and files from the source server. The task also generates a full image. You can use this image to create an instance for verification.
    2. After the first incremental migration task is complete, SMC automatically migrates incremental data and generates new images at specific time points based on the synchronization interval that you have configured.
      Note The image generated for each incremental migration task is a full image of the source server at a specific time. The image includes incremental data at the time of migration and all existing data that has already been migrated.
      In image names that are generated during incremental migration, CYCLE_X indicates that the image is generated by the Xth incremental migration task. As shown in the following figure, the sample image is generated by the second incremental migration task.Cycle

Step 3: Stop businesses and run an incremental migration task

After stopping businesses on the source server at a proper time, you can ignore the excluded data directories and run an incremental migration task again. Perform the following steps:

  1. Log on to the source server. Stop businesses that run on the source server and ignore the excluded data directories.
  2. In the SMC console, manually run the incremental migration task or wait for the task to automatically run. To manually run the incremental migration task, follow these steps:
    1. On the Migration Tasks page, find the migration task that you want to run.
    2. In the Actions column, click the More icon and choose Manual Incremental Migration from the shortcut menu.
      Manual incremental migration
    3. In the Start Migration Task message that appears, click OK.

Result

On the Migration Tasks page, wait until the task is complete.
  • If the migration task is in the Waiting state, the migration succeeds and you can obtain the image that was generated at the latest time point. This image contains all the data for the first full migration and each subsequent incremental migration of the source server.
  • If the migration task is in the InError state, the migration fails. You must check the log to fix the issue before restarting the task. For more information about common errors and solutions, see SMC FAQ.

What to do next

After you obtain the latest full image, you can perform the following operations:
  • Create an instance to verify the image. Perform the following steps:
    1. On the Migration Tasks page, find the target migration task and click Create Instance in the Actions column.
    2. On the Custom Launch tab, the Image section shows the latest full image. Configure other parameters based on your needs and purchase the instance. For more information, see Create an instance by using the provided wizard.smc-incremental-image
    3. Connect to the instance and check the target system of server migration. For more information, see How can I check my system after migrating a Windows server? or How can I check my system after migrating a Linux server?
  • Pause the incremental migration task. Perform the following steps:
    Note You can pause an incremental migration task only when the task is in the Syncing or Waiting state.
    1. On the Migration Tasks page, find the target migration task.
    2. In the Actions column, click the More icon icon and choose Pause from the shortcut menu.
    3. In the Stop Migration Task dialog box that appears, click OK.
  • Delete the incremental migration task. Perform the following steps:
    1. On the Migration Tasks page, find the target migration task.
    2. In the Actions column, click Delete.
    3. In the Delete Migration Tasks dialog box that appears, click OK.