Configuring the Target Server

Before the migration, you need to configure a target server. The target server is used to receive the data migrated from the source server, including the system, application, and service data.

When you configure the target server, you need to specify the network, migration method, target server settings, disk and partition settings, disk encryption, and other migration settings.

Prerequisites

You have prepared the account, required permissions, source and target servers, and network environment. For details, see Preparing for Migration.
You have installed and started the Agent on the source server, and the source server is displayed in the server list on the SMS console. The source server meets the following requirements:
- It is Connected to SMS.
- The migration is in the Migration Feasibility Check stage.
- The migration is in the Pending target configuration status.

Constraints

Before setting the target server, read the constraints and limitations of SMS. For details, see Server Requirements and Migration Constraints.

Procedure

Item	Description
Configuring Basic Settings	Select the region, port, and network type of the target server.
Configuring Specifications	Configure the specifications of the target server based on the specifications of the source server. There are two methods for configuring target servers. Use existing: Select a Huawei Cloud ECS as the target server. CAUTION: To ensure that the target server can start properly after the migration is complete, its disks will be formatted, and its registry and network settings will be updated. You are advised to back up data before the migration. Create new: SMS automatically purchases a target server based on the configured specifications.
(Optional) Setting the Resource Limits	Set network parameters, such as the traffic limit and overspeed threshold. Note that some parameters are supported only on Linux servers.
Starting a Migration Drill	Migration drills help you fully assess the feasibility and identify potential risks of a migration task beforehand.
Configuring Migration Parameters	Set operations after migration, for example, choose whether to enable incremental data synchronization after full replication and whether to verify data consistency.
Saving the Settings and Starting the Migration Task	Confirm the parameter settings, save the settings, and start the migration.

Configuring Basic Settings

Sign in to the SMS console.
In the navigation pane, click Servers.
In the server list, locate the source server to be migrated, and click Configure Target in the Migration Stage/Status column or choose More > Configure Target in the Operation column.

If the source server record is not found in the server migration list, see Why Wasn't My Source Server Added to the SMS Console After I Configured the Agent?

On the Configure Basic Settings page, configure parameters by referring to Table 1.

**Table 1** Parameter description
Parameter	Sub-Parameter	Description
Target Region	-	Select the region for the target server.
Target Port	-	By default, ports 22, 8900, and 8899 are enabled for Windows. For a Linux server, port 22 is enabled by default for file-level migration, and ports 22 and 8900 are enabled by default for block-level migration. NOTE: Open ports are used for the following purposes: Port 22: The initialization port of the transmission link. It is used to establish the transmission channel and can be modified in some regions. Port 8899: The control port for data transmission. It is used to transmit task control signals. It cannot be modified. Port 8900: The port for block data transmission. It cannot be modified. Pay attention to the following security notes for migration ports: During a migration, SMS uses the required ports to establish a transmission channel between the source server and the target server. To reduce security risks during the migration, SMS include the following built-in security settings: Agent image: used only during the migration and automatically uninstalled after the migration. SSL login: Password-based SSH login is disabled for the target server.Only certificate- or key-based SSH login is allowed. SSH port: The default is port 22, which can be changed in some regions. In the security group of the target ECS, allow only the required migration ports (22, 8899, and 8900), and allow access only from the IP address of the source server. Do not enable other unnecessary ports or set the source IP address to 0.0.0.0/0. CAUTION: Strictly comply with the requirements above; otherwise the target ECS may be accessed by unauthorized IP addresses over unnecessary ports, increasing the risk of being scanned, cracked, or attacked. You are responsible for any security risks caused by incorrect security group rules. Use the latest stable version of rsync if needed, and complete security configurations according to the official rsync security hardening guide. You are responsible for any security risks resulting from using an earlier version, a version with known vulnerabilities, or a version not configured in accordance with official security requirements.
Network Type	Public	(Default) Migration over the Internet requires that the target server has an EIP bound.
Network Type	Private	A Direct Connect connection, VPN connection, VPC peering connection, VPC subnet, or Cloud Connect connection must be provisioned. The private IP address of the target server will be used for migration. For details about the network scenarios and solutions for migration over a private network, see Setting Up an SMS Migration Network Using VPN, Direct Connect, and Cloud Connect.
IP Version	IPv4	IPv4 is used for data migration by default.
IP Version	IPv6	On a dual-stack network, IPv6 can be used for migration. For details about migration over IPv6, see Migrating Servers over an IPv6 Network. CAUTION: If IPv6 is selected, you can only select an existing server as the target end, instead of creating one.

Configuring Specifications

There are two methods for configuring target servers.

Use existing: Select a server created on Huawei Cloud as the target server.

To ensure that the target server can start properly after the migration is complete, its disks will be formatted, and its registry and network settings will be updated. You are advised to back up data before the migration.
Create new: SMS automatically purchases a target server based on the configured specifications.

For details about the requirements on target servers, see Target Server Requirements.

In the list of existing servers, select one that meets the specifications requirements displayed in the Recommended Target row. If no existing server meets the requirements, click Elastic Cloud Server (ECS) above the list and purchase an ECS based on the recommended specifications. For details, see Purchasing an ECS in Custom Config Mode. You can select a pay-per-use or yearly/monthly ECS.

Figure 1 Select an existing target server
Click to enlarge

If you select Create new, the system automatically recommends server specifications, including the server name, AZ, VM specifications, disk information, EIP, VPC, subnet, and security group. You can modify these settings as needed.

Figure 2 Modifying server configurations
Click to enlarge

If you select Recommend for Server Template, the system automatically creates the AZ, instance specifications, disk type, VPC, subnet, and security group during the migration. You can adjust the settings.
- If Create new is selected for VPC, the system automatically creates a VPC for the target server based on the following rules:
  - If the source server's IP address is 192.168.X.X, the system creates a VPC and a subnet that both belong to network range 192.168.0.0/16.
  - If the source server's IP address is 172.16.X.X, the system creates a VPC and a subnet that both belong to network range 172.16.0.0/12.
  - If the source server's IP address is 10.X.X.X, the system creates a VPC and a subnet that both belong to network range 10.0.0.0/8.
- If Create new is selected for Security Group, the system automatically creates a security group for the target server and allows traffic to the target server over certain ports:
  - Windows: ports 8899, 8900, and 22
  - Linux: port 22 for file-level migration
  - Linux: ports 8900 and 22 for block-level migration
If you select Custom Template for Server Template, the system automatically sets the AZ, instance specifications, disk type, VPC, subnet, and security group based on the template. You can adjust the settings. For details about how to create a custom template, see Creating a Server Template.
Configure advanced disk settings.
- Data disks must be either VBD or SCSI. VBD is the default device type for data disks. For details about disk device types, see Device Types.
- Data disks can be created as shared disks. For details about shared disks, see Managing Shared EVS Disks.
- For target servers newly created by the system, system and data disks can be encrypted. For details about shared disks, see Managing Shared EVS Disks. To enable disk encryption, you need to create an agency to authorize EVS to access KMS. After the authorization is successful, set KMS Encryption to one of the following values:
  - Select an existing key
    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 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.
  - Before the migration is complete, do not disable or delete the key used, or the migration will fail.
  - The encryption attribute of a disk cannot be modified after the disk is created.
  - Keys can be shared with accounts, not IAM users.
  - If KMS encryption is used, you will be billed for what you use beyond the free quota given by KMS. For details, see DEW Billing Overview.

(Optional) Setting the Resource Limits

Set the parameters according to Table 2.

**Table 2** Resource limit parameters
Parameter	Description
CPU Limit	These options are only available for Linux migrations. For details, see How Do I Limit Resource Allocation for the Agent in a Linux Migration?
Memory Limit
Disk Throughput Limit
Migration Rate Limit	You can limit the migration rate based on the source bandwidth and service requirements. If you do not want to limit the migration rate, set this parameter to 0. Traffic limiting is unavailable if: The migration uses an IPv6 network. Traffic Control (TC) is missing from the source server. The TC module is available, but the Class-Based Queuing (CBQ) or Hierarchy Token Bucket (HTB) module is missing.
Overrate Threshold (%)	You can regulate how much the migration rate can exceed the configured limit. If the migration rate exceeds the threshold multiple consecutive times, the migration task is automatically paused. For example, if the migration rate limit is set to 10 Mbit/s and the overrate threshold is set to 10%, the task is automatically paused when the migration rate exceeds 11 Mbit/s (110% of the limit) multiple times consecutively. CAUTION: This option is only available for Linux migrations. It will not be available or applied if: The migration uses an IPv6 network. Traffic Control (TC) is missing from the source server. The TC module is available, but the Class-Based Queuing (CBQ) or Hierarchy Token Bucket (HTB) module is missing. The installed SMS-Agent is earlier than 24.9.0.

Starting a Migration Drill

Migration drills help you fully assess the feasibility and identify potential risks of a migration task beforehand. The system verifies if security group ports are set correctly, domains connect normally, and necessary permissions are available. If issues are identified, the system offers remediations to minimize risks and disruptions during migration.

After this function is enabled, the system automatically launches a migration drill before starting the full replication. The entire migration drill takes 5 to 15 minutes, and pay-per-use resources incur costs during this period. For details, see Billing. A migration drill does not transmit source data, so the fee incurred in the drill is low.

You can review the drill results in the task details. For details, see Checking the Migration Drill Status and Report.

Configuring Migration Parameters

Set the parameters according to Table 3.

The parameters for Windows and Linux servers are different. Set their parameters accordingly.

**Table 3** Migration settings
Parameter	Sub-Parameter	Description
Start Target Upon Launch	No	The target server will be stopped after the migration is complete.
Start Target Upon Launch	Yes	The target server will be started after the migration is complete.
Migration Method	Linux block-level	Migration and synchronization are performed by block. This method is efficient, but the compatibility is poor.
	Linux File-Level	Migration and synchronization are performed by file. This method is inefficient, but the compatibility is excellent. File-level migration is used by default for Linux OSs.
	Windows Block-Level	Migration and synchronization are performed by block. Block-level migration is used by default and cannot be changed.
Enable Concurrency	Automatic	The SMS-Agent automatically configures the maximum number of migration processes allowed based on source server conditions.
Enable Concurrency	Manual	You can specify the maximum number of processes that the SMS-Agent can start concurrently for migration and synchronization tasks, respectively. This option is only available for Linux file-level migrations. For more information, see How Do I Set the Number of Concurrent Processes for a Linux File-Level Migration?
Enable Continuous Synchronization	-	Disabled: After full replication is complete, the system automatically starts the target server without synchronizing incremental data from the source server. You need to choose More > Synchronize in the Operation column to synchronize incremental data to the target server.
Enable Continuous Synchronization	-	Enabled: After full replication is complete, the system automatically starts to synchronize incremental data from the source end to the target end periodically. In this case, the target server is not started and cannot be operated. To exit this phase, click Start Target in the Migration Stage/Status column of the migration task to start the target server.
Verify Data Consistency	-	Disabled: Data consistency is not verified after full replication is complete. You can choose whether to perform data consistency check during incremental synchronization.
Verify Data Consistency	-	Enabled: Data consistency is automatically verified after full replication is performed. This is a quick verification, and only the file size and last modification time will be verified. You can modify the verification policy when you launch an incremental synchronization. Note that consistency verification cannot be performed for servers with Btrfs file systems. The following describes the parameters for data consistency verification: 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. CAUTION: 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 O:\ If you need to include any of the preceding excluded paths in the verification, refer to Modifying the Default Excluded Paths.
Resize Disks and Partitions	-	Disabled: The number of disks and partition size of the target server are the same as those of the source server.
Resize Disks and Partitions	-	Enabled: You can adjust the number of target disks and partition size. For details, see Resizing Disks and Partitions.
Transit IP Address	-	This parameter is available only for private line migration. It is used to set the transit IP address of the target server. For details about how to configure the network in this scenario, see For a Scenario Where the Source Server Has No Internet Access and Cannot Communicate with the Target Server.

Saving the Settings and Starting the Migration Task

After configuring the target server settings, review them in the summary panel and choose whether to start the migration now or later.

Saving the settings and starting the task immediately
1. Click Save and Start.
2. In the displayed dialog box, read the migration conditions and click OK. Return to the migration server list. The task status becomes Running, indicating that the migration has started.
Saving the settings and starting the task later
1. After you confirm that the settings are correct, click Save.
2. In the displayed dialog box, read the migration conditions and click OK. Return to the migration server list. The task status becomes To be started, indicating that the migration is not started.
  To start the migration, click Start in the Migration Stage/Status column.

Resizing Disks and Partitions

You can choose whether to migrate specific source partitions and then resize the paired target partitions as needed.

The restrictions on resizing Windows disks and partitions are as follows:

The system and boot partitions on Windows cannot be resized.
For a Windows server, you can upsize partitions, but you cannot downsize them.

In the Migration Settings area, enable Resize Disks and Partitions and click Resize Disks and Partitions.
Click Resize Disk and adjust the size of each disk as required. As shown in Resizing disks and partitions on Windows, you can view the resized disks at the bottom of the window.
- If the total partition size after resizing is larger than the disk size, you need to expand the disk capacity to fit the partition size.
- If the total partition size after resizing is much smaller than the disk size, you can downsize the disk.
Figure 3 Resizing disks and partitions on Windows
Click Next: Confirm. Confirm the configurations and click OK.

Once disks and partitions are resized, this function cannot be undone directly. To restore your original settings, locate the resizing task and choose More > Delete in the Operation column, and then restart the Agent on the source server to reconfigure your target server parameters.

The restrictions on resizing Linux disks and partitions are as follows:

For a Linux server using LVM, you can choose whether to migrate specific physical or logical volumes and resize the paired target volumes.
Partition resizing is not available for Btrfs partitions on Linux.
On a Linux system, the swap partition is migrated by default and cannot be changed.
You can choose to migrate all or none volume groups by using the Migrate All Volume Groups option.
If you choose to migrate none of the logical volumes in a volume group, their physical volumes will not be migrated by default.
In a Linux block-level migration, you can upsize partitions, but you cannot downsize them.
In a Linux file-level migration, you can upsize or downsize partitions. When you downsize a partition, the new partition size must be at least 1 GB larger than the used partition space. If the current size does not meet this condition, downsizing is not possible. For details, see What Are the Rules for Resizing Volume Groups, Disks, and Partitions?

In the Migration Settings area, enable Resize Disks and Partitions and click Resize Disks and Partitions.
Configure volume groups.
- If the source server uses LVM, you can resize logical and physical volumes.
- If the source server does not use LVM, skip this step.
Figure 4 Configuring volume groups
Click Next: Configure Disks.
Click Resize Disk and adjust the size of each disk as required. As shown in Resizing disks and partitions on Linux, you can view the resized disks at the bottom of the window.
- If the total partition size after resizing is larger than the disk size, you need to expand the disk capacity to fit the partition size.
- If the total partition size after resizing is much smaller than the disk size, you can downsize the disk.
Figure 5 Resizing disks and partitions on Linux
Click Next: Confirm. Confirm the configurations and click OK.

Once disks and partitions are resized, this function cannot be undone directly. To restore your original settings, locate the resizing task and choose More > Delete in the Operation column, and then restart the Agent on the source server to reconfigure your target server parameters.

Checking the Migration Drill Status and Report

If Migration Drill is enabled when you configure a migration task, you can check the migration drill status and report.

In the server list, click the name of the source server to expand the migration task details.
On the Task Progress tab, check the status and progress of the migration drill.
In the upper part of the task details page, click View Report next to Drill Status. In the report displayed on the right, check the drill details, check items, and check results.