Migrate incremental data from a VMware VM without an agent - Server Migration Center

Server Migration Center (SMC) allows you to migrate incremental data from a VMware VM to Alibaba Cloud. You can specify the time interval between incremental migration operations. Incremental migration reduces the VM downtime and the total duration of cutover. This topic describes how to migrate incremental data from a VMware VM without an agent.

Limits

When you create an incremental migration job, you must set the Destination Type parameter to ECS Image.

Procedure

Step 1: Enable CBT

In this topic, vCenter 6.7 is used. Perform the following steps to enable Changed Block Tracking (CBT). To migrate incremental data from a VMware VM, you must enable CBT for the VM. If you disable CBT, full data is migrated from the VMware VM. If CBT is already enabled, skip this step.

Warning

Before you enable CBT, make sure that no snapshots are generated for the VMware VM. Otherwise, the incremental data migrated by using CBT may be incorrect. If you delete the snapshots of the VMware VM when you enable CBT, execute the ./disk/migrate_configure file in the /root/smc directory, which is the home directory of the SMC client. This way, you can reobtain the configuration information about the VMware VM.

To enable CBT, make sure that the following conditions are met:

The version of the ESXi host is ESXi 4.0 or later.
The VM hardware version is 7 or later.
The I/O operations of the VMware VM must be performed in the ESXi storage.
The VMware VM supports Raw Device Mapping (RDM) and Virtual Machine File System (VMFS) in virtual compatibility mode and Network File System (NFS).
The VMware VM does not use independent persistent or nonpersistent disks to store data.

Log on to vCenter Server.
Right-click the VMware VM that has been powered off and select Edit Settings.
On the Edit Settings page, click the VM Options tab.
Click Advanced and then click EDIT CONFIGURATION... next to Configuration Parameters.

On the Configuration Parameters page, click ADD CONFIGURATION PARAMS and add the parameters that are described in the following table. adaaaaaa56

Name	Value	Description
ctkEnabled	TRUE	Specifies whether to use CTK files.
scsi0:0.ctkEnabled	TRUE	Specifies whether to allow the use of CTK files for the hard disk whose small computer systems interface (SCSI) ID is 0:0.
scsi0:1.ctkEnabled	TRUE	Specifies whether to allow the use of CTK files for the hard disk whose SCSI ID is 0:1.

In the scsix:x.ctkEnabled parameter, x:x indicates the SCSI ID. Replace x:x with an SCSI ID based on your business requirements. In this topic, hard disks whose SCSI IDs are 0:0 and 0:1 are used. To query the SCSI IDs of hard disks in the VM, go to the Virtual Hardware tab of the Edit Settings page. adda

Click OK. Then, right-click the VMware VM and choose Power > Power On to power on the VMware VM.
If CBT is enabled, a xx-ctk.vmdk file is added to each virtual disk and snapshot disk.

Step 2: Create and start an incremental migration job

After you import the information about a migration source in the SMC console, perform the following steps to create and start an incremental migration job. You do not need to stop your services that are running on the VM. For more information, see Migrate VMware VMs without agents.

When you create a migration job, turn on Automatic Incremental Synchronization in the Advanced Settings section.

Configure the following parameters related to automatic incremental migration:
- Automatic Incremental Synchronization: specifies whether to enable automatic incremental migration. Turn on this switch.
- Synchronization Interval: the time interval between two consecutive incremental migration operations. You can specify a time interval in the range of one hour to seven days.
- Maximum Reserved Images: the maximum number of images that can be retained during incremental migration. Valid values: 1 to 10. An image is generated for each incremental migration operation. If the total number of images exceeds the upper limit, the earliest unused image is deleted.
The migration job immediately starts after it is created. Data is migrated in the following way:
1. During the first incremental migration operation, SMC migrates all data except the excluded directories and files, and generates a full image. You can use this image to create an Elastic Compute Service (ECS) instance for verification.
2. After the first incremental migration operation is complete, SMC automatically migrates incremental data and generates images at specific points in time based on the value of the Synchronization Interval parameter.
  Note
  The image generated for each incremental migration operation is a full image of the source server at a specific point in time. The image contains the incremental data at the point in time of migration and all earlier migrated data.
3. After an incremental migration operation is complete, the migration job enters the Waiting state and runs at the next specified point in time to migrate incremental data.
Optional. You can also manually run the incremental migration job that is in the Waiting state. Perform the following steps:
1. On the OS Migration page, find the migration job that you want to run and click Manual Incremental Synchronization in the Actions column.
2. In the Manual Incremental Synchronization message, click Confirm.
  Note
  If you want to pause an incremental migration job, find the migration job, move the pointer over the icon in the Actions column and select Pause.
  If you want to delete an incremental migration job, find the migration job, move the pointer over the icon in the Actions column and select Delete.
3. View the incremental migration result.
  If the migration progress is 100%, the incremental migration is complete.

Step 3: Stop the services on the VMware VM and run the incremental migration job again

To ensure that all data can be migrated to Alibaba Cloud, stop the services on the VMware VM and run the incremental migration job during off-peak hours.

In the SMC console, manually run the incremental migration job or wait for the job to automatically run.

Note

SMC automatically runs the incremental migration job based on the value of the Synchronization Interval parameter.

Step 4: Complete incremental synchronization

After the last incremental migration operation is complete, perform the following steps to complete incremental migration.

On the OS Migration page, find the migration job that you want to manage and click Complete Incremental Synchronization in the Actions column.
In the Run Incremental Job dialog box, click OK.
You can also select Perform One Last Synchronization in the Run Incremental Job dialog box to perform the last incremental migration operation.
On the Migration Jobs page, view the status of the created job.
The amount of time required for data transmission is subject to factors such as the data size of the migration source and network bandwidth. Wait until the migration job is complete.

Verify the migration result

If the migration job enters the Completed state, the migration is successful.
After the migration is complete, an Alibaba Cloud custom image is generated. You can click View Report in the Migration Deliverables column to view the check result of the image. For more information, see View the image check result section of the "Configure image check" topic.
(Recommended) Manually verify the migration result
You can click Create Instance in the Actions column to go to the ECS instance creation page in the ECS console. The custom ECS image created by the migration job is selected by default for you to create an ECS instance. For more information, see Create an instance by using a custom image.
Use the automatic migration result verification feature
Note
To use this feature, you must install the Cloud Assistant plug-in in your instance, and the system version of the instance must support this feature. For more information, see Install Cloud Assistant Agent.
This feature uses the ACS-SMC-CreateAndVerifyInstance template provided by Alibaba Cloud CloudOps Orchestration Service (OOS) to automatically verify whether the image generated by the migration job can be used to create an ECS instance and whether the ECS instance can start as expected.
Click Verify Migration Result in the Actions column.
In the dialog box that appears, read the instructions on the verification process and click Verify Now.
You can also click Customize Verification Parameters to configure the parameters.
In the Verify Migration Result column, view the verification result. Valid values:
Verified: indicates that the migration is successful. You can click Show Output Parameters to check the details.
Not Verified: indicates that the migration failed. You can click View Cause to troubleshoot the failure.
You can also click the icon in the Actions column and select View Verification Records in OOS Console to view the template history.
After the server is migrated, you must perform the following operations to ensure normal operation of your business:
- Verify the integrity and correctness of the data. For more information, see the How do I check my system after I migrate a Linux server? or How do I check my system after I migrate a Windows server? section of the "FAQ" topic.
- Manually start the applications and services after the migration if automatic start is not enabled for the applications and services on the source server.
- Change the IP address of the server after the migration if your business involves IP address configuration.
  If a domain name has been bound to the source server, the public IP address of the server is changed after the migration. In this case, you must resolve the domain name to the new public IP address of the server For more information, see Add an A record for a website domain name.
  If you want to keep the private IP address unchanged, you can modify the private IP address after the migration is complete. For more information, see Primary private IP address.
The migration test failed if the migration job enters the Drill Exception state.
In this case, you need to check the test report, fix the test items that are in the Critical state, and then perform a test again. For more information, see Configure a migration test.
The migration failed if the migration job enters the InError state.
In this case, you need to perform the following operations:
1. Click Troubleshoot Errors in the Actions column and fix the failure based on the error code and error message. For more information, see FAQ about Server Migration Center (SMC) and Troubleshooting.
2. On the Migration Jobs page, click Retry Migration Job.
  The migration job resumes from the point where it was suspended.
  Important
  If the intermediate instance is released, you must create another migration job. For more information, see the What do I do if I release an intermediate instance by accident? section of the "FAQ" topic.

Clear resources

During the migration, SMC creates a temporary pay-as-you-go intermediate instance named No_Delete_SMC_Transition_Instance within the destination Alibaba Cloud account. The method to clear resources depends 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, choose > Delete in the Actions column to delete the migration job and release the intermediate instance at a time.
- Manually release the intermediate instance. For more information, see Release an instance.