Creating a Server Migration Workflow

Constraints

• A workflow can contain a maximum of 100 servers.
• You can migrate a maximum of 1,000 servers concurrently. For any servers beyond this number, the workflows will pause at the first step and put these servers in a pending state until other servers complete their migration. The workflows will then automatically start on these servers in the order 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.

Notes

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

Prerequisites

• You have discovered source servers.
• Servers to be migrated have been added to an application, and the application servers have been assessed. For details, see Grouping Resources as Applications and Getting Target Recommendations. After the assessment is complete, you can purchase recommended target servers in batches. For details, see Purchasing Resources. Source servers with target servers associated do not need to be assessed. For details, see Associating Source Servers with Target Servers.

Procedure

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 Migrate > Workflows.
3. Click Create Workflow in the upper right corner of the page.
4. In the Server Migration card, click Preview Steps to view the steps predefined in the template and the detailed description of each step. If the type of a step is Automated, the step is automatically performed by MgC. If the type of a step is Manual, you need to perform the step manually. Click Next: Configure Workflow in the lower right corner.
5. Configure the workflow parameters based on Table 1.

   Table 1 Parameters for configuring a server migration workflow

   Area	Parameter	Description
   Workflow Details	Name	User-defined
   	Description
   	Select Source Resources	By application: Servers in the selected application will be migrated together. By migration plan: Servers in the selected migration plan will be migrated together.
   Application	Application	If Select Source Resources is set to By application, select the application that contains the servers to be migrated.
   Migration Plan	Migration Plan	If Select Source Resources is set to By migration plan, select the plan that contains the servers to be migrated. For details about how to create a migration plan, see Creating a Server Migration Plan.
   Migration Network	Network Type	If you select Public, ensure that all target servers have EIPs bound. These EIPs will be used for the migration.
   		If you select Private, configure Direct Connect connections, VPN connections, VPC peering connections, or subnets in the target VPC in advance to ensure that the source environment can access the target environment. If the source environment does not have direct Internet access, you need to enter the private IP address of the source proxy server and the port used by the proxy software. If the source proxy server cannot access the Internet, put the SMS-Agent installation package at a location where the source servers can access directly or over a proxy. You can download the SMS-Agent installation package from the SMS console.
   Target Environment	Region	The target region. It defaults to the one you selected when you assessed the application.
   	Project	A project in the target region.
   	VPC	If the source IP address is 192.168.X.X, you are advised to create a VPC and a subnet that both belong to network range 192.168.0.0/16. If the source IP address is 172.16.X.X, you are advised to create a VPC and a subnet that both belong to network range 172.16.0.0/12. If the source IP address is 10.X.X, you are advised to create a VPC and a subnet that both belong to network range 10.0.0.0/8.
   	Subnet	The subnet has to be in the same network segment as the VPC.
   	Security Group	If there are Windows source servers, the security group must allow access on ports 8899, 8900, and 22. If there are Linux source servers, the security group must allow access on port 22. CAUTION: For security purposes, you are advised to only allow traffic from the source servers on these ports. The firewall of the target servers must allow traffic to these ports.
   	Migration Port	It defaults to 22. If port 22 is occupied, you can use one from 10000 to 65535. CAUTION: The following ports cannot be used as the migration port: 135, 139, 445, 5357, 5985, 5986, 8899, 8900, 47001, 49664, 49665, 49666, 49668, 49669, 49671, 49674, 49677, 49679, 49680, 49681, 49682, 49683, 49685, 49690, 49691, 49693, 49694, 49695, 49698, 49699, 49700, 49702, 49703, 49704, 49705, 49706, 49707, 49708, 49709, 49710, 49711, 49712, and 49713 Make sure the entered port is not in the blacklist and is not being used by other services on the source server. Additionally, check that the network environment allows traffic to this port. The functions of the port are as follows: For Linux servers, this port is used to establish transmission channels and transmit data. For Windows servers, this port is used to establish transmission channels.
   	Control Port	This port is used to transmit task control signals for Windows servers. It defaults to 8899 and cannot be changed.
   	Transmission Port	This port is used to transmit data for Windows servers. It defaults to 8900 and cannot be changed.
   	Encryption	If you select No, the system and data disks will not be encrypted for target server newly created in the workflow.
   		If you select Yes, the system and data disks will be encrypted for target servers newly created in the workflow. NOTICE: This setting does not apply to existing target servers associated with the source servers. This setting applies to all target servers newly created by the workflow. The disks on these new target servers will be encrypted using the same key. The encryption attribute of a disk cannot be modified after the disk is created. Keys can be shared with accounts, not users. To enable disk encryption, you need to create an agency to authorize EVS to access KMS. If you have the right to grant the permissions, grant the KMS access permissions to EVS directly. After the authorization succeeds, you do not need to perform the authorization again. If you do not have the right to grant the permissions, contact a user with the Security Administrator permissions to grant you the right and then repeat the preceding operations. After the authorization is successful, configure the following parameters: Select an existing key NOTICE: Only enabled keys generated using the AES_256 encryption algorithm are supported. Select a key from the drop-down list. You can select one of the following keys: Default keys: After the KMS access permissions have been granted to EVS, the system automatically creates a default key and names it evs/default. Custom keys: You can choose an existing key or create a new one. For details about how to create a key, see Creating a Key. Enter a key ID Enter the ID of a key shared from another user. Ensure that the key is in the target region. For details, see Creating a Grant.
   Advanced Settings	Verify Data Consistency	If you select Yes, the system will automatically verify data consistency after the full replication is complete. This is a quick verification, and only the file size and last modification time will be verified. You can modify the verification policy after the incremental synchronization is complete. If you select No, data consistency will not be verified after the full replication is complete. You can modify the verification policy after the incremental synchronization is complete.
   	Start Target After Migration	If you select No, the target servers will be stopped after the migration is complete. If you select Yes, the target servers will be started after the migration is complete.
   	Set Bandwidth Limit	If you select No, the migration traffic is not limited. If you select Yes, you can limit the bandwidth that can be used for migration based on the source bandwidth and service requirements. CAUTION: Consider the migration scale to set an appropriate bandwidth limit. If a too small bandwidth is allocated to the workflow that includes 10 servers, migration tasks in the workflow may preempt the limited bandwidth resource, and some servers may fail to be migrated.
   	Install rsync on Source	If you select No, the rsync component will not be installed on the source servers. If you select Yes, the rsync component will be automatically installed on the source servers. CAUTION: Linux migrations depend on rsync. If rsync is not installed on a source server, the server will fail to be migrated.
   	Retain IP Address	Enable this option to retain the private IP addresses of the source servers on the target servers. Enabling it may cause risks. You need to evaluate and take responsibility for any potential risks.
   	Enable Quick Mode	Enable this option if incremental synchronization is not required. This option is disabled by default. If it is enabled, incremental synchronization is skipped and then subsequent steps are performed after full replication is complete in the workflow. Set this option based on your requirements.
   	Enterprise Project	Select the enterprise project you want to migrate to. The enterprise project default is selected by default.

6. Click Next: Confirm.
7. Confirm the workflow settings and click Confirm. The Run Workflow dialog box is displayed, which indicates that the workflow has been created.
   • If you want to start the migration immediately, click Confirm to run the workflow.
   • If you want to add a stage or step to the workflow, click Cancel. The workflow enters a Waiting state, and the migration is not started. To start the migration, click Run in the Operation column.

8. On the migration workflow details page, view the workflow settings and the migration progress. After the step for starting the migration Agent is completed, a migration task is automatically created on the SMS console. For details about the server information mapping between MgC and SMS, see What Are the Information Mappings Between MgC and SMS?
   • Move the cursor to the migration progress bar. In the box that is displayed, view more migration details.
   • When the migration progress bar reaches a step that requires manual confirmation, move the cursor to the progress bar and click Confirm next to the step status in the displayed window, so that the subsequent migration steps can be executed.
   • When the workflow reaches the ResizeDiskPartition step, the system identifies whether disk capacity reduction has been performed on the target server.
     • If yes, go to SMS console and resize disks and partitions for the target server. For details, see the Partition Resizing parameter in Configuring a Target Server. After the adjustment is complete, go back to the MgC console and click Confirm next to the step status so that the workflow can continue.
     • If no, skip this step.
   • The StartSynchronization step is repeated before you verify your services on the target server.
   • When the progress bar reaches Cutover, 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, click Confirm in the workflow. The system automatically performs the following steps SourceClear and MigrationTaskClear.

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.

  Figure 1 Retry
  

  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. After the migration task is cleared, the workflow starts from the StartUpAgent step to restart the SMS-Agent process on the source server and create an SMS migration task again.

  Figure 2 Full Retry
  

  

  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 incremental synchronization is complete, you can modify the consistency verification policy.

1. Move the cursor to the progress bar. In the dialog box, click Modify next to Consistency Verification Policy.
   Figure 3 Modifying the consistency verification policy
   

2. Select Verify Data Consistency and configure the verification policy based on Table 2.
   Figure 4 Configuring the consistency verification policy
   

   Table 2 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.