Creating a Batch Server Migration Workflow

Constraints

• A workflow can contain a maximum of 100 servers.
• Source servers in workflows created by the same user must have unique MAC addresses. Duplicate MAC addresses may cause network conflicts or task execution errors.
• A maximum of 1,000 servers can be migrated at the same time. Any additional servers beyond this limit will cause workflows to pause at the initial step and remain in a pending state. Whenever any ongoing migration completes, a paused workflow will automatically resume, following the order in which the workflows were created.
• If this is your first time to create a server migration workflow, you need to delegate MgC the required permissions. For more information about the required permissions, see Agency Permissions.

Precautions

Before creating a server migration workflow, read and understand the precautions below.

Procedure

Figure 1 shows the process of creating a workflow for server migration.

Figure 1 Server migration process

Step	Description
Preparations	Sign up for a HUAWEI ID, enable Huawei Cloud services, and top up your account. Create an IAM user and obtain the required permissions and an access key for the user. For details, see Preparations.
Create an application migration project.	Create a project to segregate and manage your migration resources. For details, see Creating an Application Migration Project.
Install the MgC Agent and connect it to MgC.	The MgC Agent is a tool used to discover resources and collect their details. It is also used for executing migration workflow tasks. For more details, see: Install the MgC Agent on Windows. Connect the MgC Agent to MgC.
Discover source servers.	Discover source servers and collect their details. MgC provides the following methods for you to do this work. Online Discovery Intranet Discovery Manual Addition Importing RVTools Data Importing Details of Cloud Resources
Create a server migration plan.	Create a migration plan to outline the servers to be migrated together and configure the target servers. For details, see Creating a Batch Server Migration Plan.
Create a server migration workflow.	After the preceding steps are complete, create a server migration workflow.

Creating a Server Migration Workflow

1. Sign in to the MgC console. In the navigation pane, under Project, select an application migration project from the drop-down list.
2. In the navigation pane, choose Migration Workflows (NEW).
3. On the Workflows tab, click Create Workflow to open the Select Creation Method page.
4. Select the created server migration plan from the Migration Plan drop-down list and click OK. Only complete migration plans can be selected. For details about how to create a server migration plan, see Creating a Batch Server Migration Plan.
5. In the Workflow Basics area, specify a workflow name or use the name preset by the system and enter a description (optional).
6. In the Resource Settings and Migration Settings areas, check whether the resource and migration settings inherited from the selected migration plan meet your requirements. If you need to modify these settings, click Modify Migration Plan in the lower right corner of the page and update the migration plan settings.
7. Confirm the settings and click Create Workflow in the lower right corner of the page. The Start Workflow dialog box is displayed, indicating that the workflow has been created.
   • If you want to start the migration immediately, click Confirm to run the workflow.
   • If you want to save the migration workflow without starting the migration, click Cancel. The migration workflow will move to a Waiting status, and the migration has not started yet. To run the workflow, click Run in the Operation column to manually start the migration. If you need to add checkpoints to the workflow to control the migration process, see Adding a Stage or Step.

8. In the workflow list, click the workflow name. On the Workflow Details page, you can review the workflow status, progress, and migration progress of the resources contained in the workflow.
   

   When the workflow on a resource reaches a step requiring manual confirmation, choose More > Confirm in the Operation column, or click the resource name. In the displayed page, click Confirm. The workflow will then continue with the remaining migration steps.

   You can perform the following operations on the resources included in the workflow:

   • Click a resource name. On the Resource Details page displayed on the right, you can review the basic information, migration status, and migration progress of the resource.
   • After the step CreateTargetServer is complete for a resource, choose More > View Target Resource in the Operation column to review details about the target server.
   • After the step StartUpAgent is complete for a resource, a migration task is automatically created on the SMS console. Click View Migration Task in the Operation column to view the task details on the SMS console.
   • When the workflow on a resource reaches the ResizeDiskPartition step, the system identifies whether disk capacity reduction has been performed for the target server.
     • If yes, go to the SMS console and resize disks and partitions for the target server. For details, see the Resize Disks and Partitions parameter in Configuring a Target Server. After the adjustment is complete, return to the workflow details page and choose More > Confirm in the Operation column to continue the migration.
     • If no, skip this step.
   • The StartSynchronization step can be repeated. When the workflow on a resource reaches the BusinessValidation step that awaits confirmation, you can select the resource and click Run Previous Step above the list to launch an incremental synchronization again. You can also click the resource's name and on the displayed page, click Run Previous Step in the Migration Status area.
   • When the workflow on a resource reaches the Cutover step, the migration is complete. You need check whether your service systems are running properly on the target server. If they are, manually switch services to the target server. After the switchover is complete, return to the workflow details page and choose More > Confirm in the Operation column. The system automatically performs the subsequent SourceClear and MigrationTaskClear steps.

When to Use the Retry and Full Retry Buttons

During the running of the server migration workflow, the MgC Agent (formerly Edge) launches an SMS-Agent migration process on each source server. After the process is started, it communicates with the SMS console and receives commands to perform migration. During the StartMigration and StartSynchronization steps in the workflow, if the SMS-Agent process on a source server disconnects from the SMS console, the MgC console will detect the disconnection, causing the migration workflow to fail on that source server. On the migration workflow details page, you will see options Retry and Full Retry. The appropriate choice depends on the cause of the disconnection. The possible causes for the disconnection include:

• Possible cause 1: There is a network exception.

  In this case, the SMS-Agent process still opens on the source server. You only need to restore the network, wait until the connection to the SMS console is restored, and click Retry to resume the migration.

  Command for checking the SMS-Agent process on Linux:

  # ps -ef | grep -v grep | grep linuxmain

  Command for checking the SMS-Agent process on Windows:

  # Get-Process -Name SMSAgentDeploy -ErrorAction SilentlyContinue

• Possible cause 2: The SMS-Agent process is stopped due to a restart of the source server.
  In this case, the SMS-Agent process is stopped, and the migration cannot be resumed. You need to create an SMS migration task again by clicking the Full Retry button. Then the workflow will directly go to the MigrationTaskClear step. After the migration task is cleared, the workflow will start from the StartUpAgent step to restart the SMS-Agent process on the source server and create an SMS migration task again.

  

  Clicking the Full Retry button will delete the original migration task and create a new one. The migrated data will be overwritten.

Modifying the Data Consistency Check Policy After Incremental Synchronization Is Complete

After the StartSynchronization step on a resource is complete, you can modify the consistency verification policy.

1. Click the resource's name. In the displayed dialog box, click Modify next to Consistency Verification Policy.

2. Select Verify Data Consistency and configure the verification policy based on Table 1.

   Table 1 Parameters for configuring the consistency verification policy

   Parameter	Description
   Enable Hash Verification	If this option is enabled, the system will generate and compare hash values for each file to be verified. Hash verification is recommended when individual files are large and important. Enabling this option will increase CPU and disk I/O overheads for the source server and extend the verification time. CAUTION: Hash values cannot be calculated for files in use, so these files will be skipped during the verification. Enabling this option requires you to specify the verification scope, and only files in the specified scope will be verified.
   Verification Scope	Under Exclude paths, enter the paths you want to exclude from the verification. A maximum of 30 paths can be entered. Use commas (,) to separate the paths. For example, /root/data,/var. Leaving it empty will initiate a full verification. Under Include paths, enter the paths you want to verify. NOTICE: If the entered paths are incorrect or empty, 0 will be displayed for them in the verification results. The more data you need to verify, the longer the verification will take. It is wise to narrow the verification scope to only key paths. The following paths will be excluded from consistency verification by default: Linux: /bin, /boot, /dev, /home, /etc, /lib, /media, /proc, /sbin, /selinux, /sys, /usr, /var, /run, and /tmp Windows: top-level directories of partitions, for example, C:\ and D:\.
   Verify Inconsistencies	This option can only be enabled after at least one consistency verification is complete.

3. Click Save. After the incremental synchronization is complete, the system will automatically verify data consistency.
4. After the synchronization and verification are complete, go to the SMS console and view the verification results.