Agentless migration for VMware virtual machines (VMs) is non-intrusive and does not consume compute resources on the guest operating system. This approach does not impact server security or performance. This topic describes how to migrate VMware VMs by using Server Migration Center (SMC).
You can also migrate VMware virtual machines by using the agent-based approach. For more information, see Migrate servers to Elastic Compute Service (ECS).
Migration scenarios
Due to a change in the technical solution for intermediate instances, Server Migration Center (SMC) will no longer support migrating Windows servers to destination instances in regions outside the Chinese mainland after November 30, 2025 (UTC+8). Before this date, you can still use SMC client V2.8.5 and earlier versions. For more information about the change and its impact, see [Product Change] Announcement on SMC no longer supporting the migration of Windows servers to destination instances in regions outside the Chinese mainland.
(Recommended) Migrate a server to an Alibaba Cloud ECS custom image.
If you have not purchased an Alibaba Cloud ECS instance, you can migrate your server to an Alibaba Cloud ECS custom image. Then, you can manually create an ECS instance from the custom image.
Migrate a server to a purchased Alibaba Cloud ECS instance.
If you have an existing Alibaba Cloud ECS instance with storage, an operating system, and other configurations that are compatible with the source server, you can migrate the source server to that instance.
WarningAfter the migration, the original data on the destination ECS instance is erased. The data on the source server is not affected. Therefore, do not use this migration method if the destination ECS instance contains important data.
Limitations
Environment requirements
The following table lists the environment requirements for each OVA template.
OVA template | Connector requirements | vCenter deployment | Standalone ESXi deployment |
SMC VMware Connector 6.7 OVA |
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SMC VMware Connector 8.0 OVA |
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Supported operating systems
The Server Migration Center (SMC) client automatically detects the operating system of the VM to be migrated. Supported operating systems are listed below. To check your operating system, run the cat /proc/version or systeminfo command.
CentOS
Ubuntu
SUSE
OpenSUSE
Debian
RedHat
Others Linux
Windows Server 2003
Windows Server 2008
Windows Server 2012
Windows Server 2016
Windows Server 2019
Windows Server 2022Disk size limitations
Server Migration Center (SMC) limits the size of disks for migration. Disks exceeding these limits cannot be migrated. If a disk is too large, you must transfer its data by using another method, such as cp or sftp.
System disk: The maximum capacity is 2 TiB.
Data disk: The maximum capacity is 32 TiB.
Roles and permissions
If you use a vCenter user, the role assigned to the user on the ESXi host and VM must have the following permissions:
Datastore > Browse datastore
Datastore > Low-level file operations
Host > Local operations > Create virtual machine
Virtual machine > Change Configuration > Acquire disk lease
Virtual machine > Change Configuration > Toggle disk change tracking
Virtual machine > Provisioning > Allow virtual machine download
Virtual machine > Provisioning > Allow disk access
Virtual machine > Provisioning > Allow read-only disk access
Virtual machine > Snapshot management > Create snapshot
Virtual machine > Snapshot management > Remove Snapshot
If you use an ESXi user, the role must be Administrator.
Migration fee
Server Migration Center (SMC) is available at no additional charge. However, you will incur charges for the Elastic Compute Service (ECS) resources used during the migration, such as intermediate instances and cloud disks. For more information about billing, see SMC Billing Items.
Prerequisites
Complete the pre-migration preparations. For more information, see Pre-migration preparations.
To prevent data loss, back up important data to an image, a snapshot, or an external storage device.
If you are migrating a source server to an existing ECS instance:
The operating system of the target instance must match that of the source server. For example, both must be Linux or both must be Windows.
The target instance must have at least as many data disks as the source server. If it does not, you must attach data disks.
Procedure
Step 1: Create a VMware agentless connector
Server Migration Center (SMC) provides an Open Virtualization Appliance (OVA) template. You can import this template into your vCenter or ESXi environment to deploy a VMware agentless connector.
An Open Virtualization Format (OVF) is an open standard that describes a portable, secure, efficient, and extensible format for packaging and distributing virtual appliances. An OVF package typically consists of several files, such as an .ovf manifest, an .mf file, a .cert file, .vmdk files, and .iso files. An OVA is a single-file distribution of an OVF package.
VMware vSphere is a virtualization platform that transforms data centers into aggregated computing infrastructures that include CPU, storage, and networking resources. vSphere manages these infrastructures as a unified operating environment and provides tools to manage the data centers. The two core components of vSphere are ESXi and vCenter Server. ESXi is the virtualization platform used to create and run virtual machines (VMs) and virtual appliances. vCenter Server is a service used to manage multiple connected hosts in a network and to pool their resources.
Download and decompress the OVA template
Click Download OVA template. In the Import Instructions section, download and decompress the OVA template for your VMware ESXi or vCenter version.
Deploy the VMware agentless connector
Import the VMware agentless connector OVA template into your vCenter or ESXi environment to deploy it. You can deploy the connector in either a vCenter or a standalone ESXi environment.
Deploy in vCenter (recommended)
Import the VMware agentless connector OVA template into your vCenter environment to deploy the connector. The following steps use vCenter 6.7 as an example.
Log in to vCenter. Right-click the vCenter host and select Deploy OVF Template....
On the Deploy OVF Template page, follow the wizard to create the virtual machine (VM).
Select the OVA template and click NEXT.
Select Local file, click Browse..., and select the decompressed OVA template file.
Specify a name and location for the VM, and then click NEXT.
Enter a name in the Virtual machine name field and select a deployment location.
Select a compute resource and click NEXT.
Verify the template details and click NEXT.
Select a storage location and click NEXT.
Select a network and click NEXT.
Review the configuration details and click FINISH.
After the deployment is complete, right-click the VMware agentless connector and select Power > Power On.
Configure the network to allow the deployed VMware agentless connector to connect to port 443 (default) of vCenter and port 902 (default) of the ESXi host of the VM you want to migrate.
On the Summary tab, obtain the IP address of the VMware agentless connector.
Deploy in standalone ESXi
Import the VMware agentless connector OVA template into your ESXi environment to deploy the connector. The following steps use ESXi 7.0 as an example.
Log in to VMware ESXi. Right-click Virtual Machines and select Create/Register VM.
On the Select Creation Type page, select Deploy a virtual machine from an OVF or OVA file and click Next.
On the Select OVF And VMDK Files page, enter a name for the VM, click Click To Select Files Or Drag/drop to select the downloaded OVA template file, and then click Next.
On the Select Storage page, click Next.
On the Deployment Options page, click Next.
On the Ready To Complete page, click Finish.
Wait for the VM to be deployed. The IP address of the connector is displayed in the General Information section. By default, the connector network is configured by using DHCP. You can change the network configuration as needed.
Configure the network to allow the deployed VMware agentless connector to connect to ports 443 and 902 (default) of the ESXi host.
Step 2: Import the migration source
Log in to the VMware agentless connector, add and configure the source VMs, and then run the import command in the connector to import the VMs into the Server Migration Center (SMC) console.
Add source VMs
Use the configure.sh script to add the source VMs. You can add multiple VMs at once, and the corresponding number of migration sources will appear in the SMC console.
A single VMware agentless connector can import and manage a maximum of 10 active migration sources at one time. If you configure more than 10 VMs, only 10 migration sources will appear in the SMC console. The remaining sources will be automatically imported after the current Migration Tasks are completed.
The operating system type preset in VMware vCenter may not be accurate. You must verify the actual operating system.
Log in to the VMware agentless connector.
The following steps use an SSH remote connection as an example:
In a terminal that can connect to the VMware agentless connector, run the following command to remotely connect to the connector. The default username is
root, and the password is empty by default.ssh root@<IP address of the VMware agentless connector>ImportantFor security, we recommend that you change the password immediately.
Run the following command to check whether the time is correct.
dateIf the time is incorrect, use the ntpdate command to calibrate it. This example uses the
0.asia.pool.ntp.orgtime server.ntpdate 0.asia.pool.ntp.org hwclock --systohcWarningIf the time is incorrect, the migration source import will fail.
Run the following command to configure vCenter or ESXi and the source VMs.
NoteThis step retrieves a list of all hosts and VMs in the environment. If you already know the name of the host or VM you need to configure, you can skip this step and specify the name directly. For more information, see How do I directly specify a VM or a VM under a host for agentless migration of VMware VMs?.
cd /root/smc bash configure.shEnter the IP address, username, password, and port number (the default is 443) of VMware vCenter or ESXi in sequence. The output is similar to the following.
[root@localhost ~]# cd /root/smc [root@localhost smc]# ./configure.sh Please input vCenter/ESXi IP:192.168.XX.XX Please input username:administr****@vsphere.local Please input password: Please input port number(default 443):443A connection success message appears, and a list of hosts is generated. You are prompted to enter the ID of the host where the source VM resides. You must select a host with a status of 'Connected' (indicated by an asterisk * in the Connected column).
Test to connect the vCenter/ESXi... Connect success! save to ./vmware_connect_config.json ========Aliyun SMC VMware Configure Tool 1.2======== Connect success! Getting host list progress: [>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>100.00%]time：1.0s Host List: ------------------------------------------------------------------------ ID Name Version Connected 1 192.168.XX.XX 6.7.0 * 2 192.168.XX.XX 7.0.3 * ------------------------------------------------------------------------ Please input the ID of Host(input 0 to exit):1After you enter the host ID, a list of VMs is generated. You are prompted to enter the ID of the source VM. You must select a VM with a status of 'Connected' (indicated by an asterisk * in the
Connectedcolumn).Test to connect 192.168.XX.XX Connect success! Getting vm list progress: [>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>100.00%]time：2.3s VM List of 192.168.XX.XX: ------------------------------------------------------------------------ ID Name Connected CBT Add 1080 test1 * 1084 win16bios * 1011 centos7-bios-2 * 3008 centos7-uefi * 2001 centos-hw10 * ------------------------------------------------------------------------ Please input the ID of VM to be migrated (input 0 to exit):1084Select the architecture of the source VM.
-------------------------------------------------------------- 0 x86_64 1 i386 2 arm64 -------------------------------------------------------------- Please choose the architecture:0If the operating system of the current VM is not automatically detected, enter the number corresponding to the correct operating system from the list provided. For example, enter 10.
------------------------------------------------------------------------ 0 CentOS 1 Ubuntu 2 SUSE 3 OpenSUSE 4 Debian 5 RedHat 6 Others Linux 7 Windows Server 2003 8 Windows Server 2008 9 Windows Server 2012 10 Windows Server 2016 11 Windows Server 2019 12 Windows Server 2022 ------------------------------------------------------------------------ Current OS [Apple macOS 10.14 (64-bit)] is invalid, please choose the OS of VM:10An asterisk (
*) in theAddcolumn next to the VM name indicates that the VM was added successfully.VM List of 192.168.XX.XX: -------------------------------------------------------------- ID Name Connected CBT Add 481 TEST_CLONE_1 * 389 win16bios * * 338 hanjun_test_001 * 386 Aliyun_SMC_Agent_6.5 * 393 win16uefi -------------------------------------------------------------- Please input the ID of VM to be migrated (input 0 to exit):0NoteTo migrate multiple VMs, continue entering the IDs of the VMs.
If you are migrating only one VM, enter 0 to return to the host selection. To migrate VMs from other hosts, repeat the previous steps. Otherwise, enter 0 again to exit the configuration.
(Optional) Configure source VMs
Use the vmware_migrate_config.json file to confirm and modify VM properties, such as the operating system, disks, and migration status.
Run the following command to view the generated vmware_connect_config.json and vmware_migrate_config.json files.
llThe output is similar to the following.
[root@localhost smc]# ll total 5588 drwxrwxrwx. 4 root root 239 Oct 17 17:27 Check -rwxrwxrwx. 1 root root 6884 Oct 14 15:54 client_data -rwxrwxrwx. 1 root root 151 Oct 14 17:47 configure.sh drwxrwxrwx. 2 root root 72 Nov 1 01:15 dist -rwxrwxrwx. 1 root root 38878 Oct 14 15:54 EULA drwxrwxrwx. 2 root root 4096 Oct 17 17:27 Excludes -rwxrwxrwx. 1 root root 5633792 Oct 31 19:43 go2aliyun_client -rwxrwxrwx. 1 root root 146 Oct 14 15:54 user_config.json -rw-r--r--. 1 root root 263 Nov 10 18:05 vmware_connect_config.json -rw-r--r--. 1 root root 18406 Nov 10 18:07 vmware_migrate_config.jsonCheck whether the properties of the VM, such as the operating system, disks, and migration status, meet your expectations.
vim vmware_migrate_config.jsonThe
vmware_migrate_config.jsonfile is in JSON format. Each VM corresponds to a key-value pair, where the key is the VM's Moref ID (a unique identifier for objects and resources in a VMware vSphere environment) and the value contains the VM's properties. The key-value pair for each VM is as follows:"1": { "vm_name": "centos7-bios-main", "moref_id": "1", "uuid": "1:525794aa-d3e9-2332-5d78-78a6e6d6d4f3:564dfd2b-91ab-1cae-2bef-cda625472b28", "cores": 2, "memory": 4.0, "boot_mode": "bios", "vdisk_num": 3, "host": "localhost.localdomain", "cpu_info": "Intel(R) Xeon(R) Platinum 8269CY CPU @ 2.50GHz", "virt_type": "VMware7,1", "host_id": "ddbd4d56-f407-f342-a8fa-2edd5424b34e", "CBT_enabled": true, "power_state": false, "connect_state": true, "mac": "unavailable", "tools_state": false, "ipv4": null, "guestOS": "CentOS 7 (64-bit)", "host_name": null, "disk": [ { "key": 2000, "uuid": "6000C296-2b4b-5c40-2d8b-dfbc757641a2", "capacity": 20971520, "file_name": "[datastore1] centos7-bios/centos7-bios-000009.vmdk", "change_id": "52 fc 41 38 48 e7 cc cc-cd af c1 f8 44 f3 0d e9/21", "system_disk": true, "migrate": true }, { "key": 2002, "uuid": "6000C294-4055-f564-1190-e365396eb0a6", "capacity": 22020096, "file_name": "[datastore1] centos7-bios/centos7-bios_2-000009.vmdk", "change_id": "52 74 c8 ba 23 f6 cd 8b-2c c5 94 40 cd b1 f5 e9/21", "system_disk": false, "migrate": true }, { "key": 2003, "uuid": "6000C296-24cf-80d2-e692-67a938ad036c", "capacity": 24117248, "file_name": "[datastore1] centos7-bios/centos7-bios_3-000009.vmdk", "change_id": "52 6a de 0a 18 b4 2a 63-46 54 19 ad 07 88 bd 16/21", "system_disk": false, "migrate": true } ], "architecture": "x86_64", "platform": "CentOS", "migrate": true, "hardware_version": 19, "host_version": "7.0.3", "snapshot_state": trueConfigure the properties of the VM, such as the operating system, disks, and migration settings. You may need to edit the following fields:
platform: The operating system of the VM. If the auto-detected OS is incorrect, you must manually set it to one of the supported operating systems listed below. SMC cannot migrate other operating systems.
CentOS Ubuntu SUSE OpenSUSE Debian RedHat Others Linux Windows Server 2003 Windows Server 2008 Windows Server 2012 Windows Server 2016 Windows Server 2019 Windows Server 2022disk: The list of disks for the VM, in array format.
The system disk is the first disk by default, and its corresponding
system_diskvalue istrue. If the system disk of the virtual machine is not the first disk, you must change thesystem_diskvalue for the actual system disk totrue, and change thesystem_diskvalue for the other data disks tofalse.By default, the
migratevalue for all disks istrue, which indicates that the disk will be migrated. If you do not want to migrate a specific data disk, change itsmigratevalue tofalse.
migrate: Whether to migrate the VM.
For a selected VM, a
migratevalue oftruemeans the VM will be migrated.To migrate a VM whose
migratevalue isfalse, change itsmigratevalue totrueand manually configure theplatformandarchitecture.architectureis the architecture of the virtual machine. Valid values arex86_64/i386/arm64.
Import the migration source
In the VMware agentless connector, run the SMC client from the command line to import the VMware VM information into the SMC console.
Accidental snapshot deletion
While the SMC client is running, do not manually shut down, restart, create, or delete snapshots for the source VM. Doing so can cause the migration to fail. If this causes a failure, run ./dist/migrate_configure in the SMC client's home directory (/root/smc) to refresh the VM configuration. Then, run the
./go2aliyun_client --reruncommand to restart the client.Manually clean up residual snapshots
During the synchronization phase, the SMC client automatically creates a snapshot named in the format
smc_MigrationTaskID_CurrentTime, for example,smc_j-bp1ho******4_2025-07-02-17:05:43. The snapshot is automatically deleted after synchronization is complete. If you manually delete the Migration Task before synchronization finishes, this action may leave a residual snapshot. To resolve this issue, follow these steps:Step 1: Manually delete the snapshot
In the vCenter/ESXi management interface, manually delete the snapshot. Right-click the source VM, select Snapshots > Manage Snapshots, select the snapshot, and click DELETE.
Step 2: Run the following commands in the SMC client home directory to refresh the VM configuration and restart the client.
cd /root/smc ./dist/migrate_configure # Refresh the VM configuration. ./go2aliyun_client --rerun # Restart the SMC client.
Go to the SMC console - Agentless Migration of VMware VMs page.
On the Agentless Migration of VMware VMs page, click Import Migration source.
On the Import Migration Source page, configure the parameters.
The following table describes the parameters.
Parameter
Description
Migration Source Type
VMware VM.
Import Method
Use Server Migration Connector to Import VMware VM is selected by default and cannot be changed.
Description
Follow the import instructions to import the migration source.
Obtain an activation code.
(Recommended) Obtain an activation code: An SMC activation code (Access Token) consists of an Access Token ID and an Access Token Code. If you do not have one, click Generate in the Description section of the SMC console and copy the code.
Log on to the VMware agentless connector and run the following commands in sequence to import the migration source.
chmod +x ./go2aliyun_client ./go2aliyun_clientEnter the activation code as prompted. The output is similar to the following. When the message
Import Source Server [s-bp14zd35128xgjdbh****] Successfully!appears, the migration source has been imported successfully.NoteRun
./go2aliyun_client --helpto obtain help information.If importing the migration source fails due to an incorrect activation code, you can re-import it. The command is
./go2aliyun_client --accesstokenid=at-****** --accesstokencode=yK******9I.You can also activate the SMC client by using an AccessKey pair. An AccessKey pair for an Alibaba Cloud account consists of an AccessKey ID and an AccessKey secret. If you have not created an AccessKey pair, create one first. For more information, see Create an AccessKey pair. The command is
./go2aliyun_client --accessid=****** --secretkey=******9I.
On the Agentless Migration of VMware VMs page in the SMC console, check the status of the migration source in the Real-time Migration Status column.
If the status is Source Online, the import succeeded.
If the status is any other value, the import has failed. To resolve the issue, refer to the following solutions and then try the import again.
Resolve the issue based on the error message in the console or by checking the log files in the SMC client directory. The default installation directory for the SMC client is /root/smc/.
For more information about common issues and solutions, see SMC FAQ and Troubleshoot errors.
Step 3: Create a Migration Task
In the SMC console, create and start a Migration Task as prompted. SMC supports migrating VMware servers to the following Destination Type options:
(Recommended) ECS Image: Converts the server into a custom image. You can then use the custom image to create an ECS instance.
ECS Instance: Migrates the VMware VM directly to an existing ECS instance. This is suitable if you have a newly purchased instance or an existing one whose data is no longer needed. The number and size of storage volumes, the operating system, and other configurations of the VMware VM must be compatible with the target ECS instance.
WarningAfter you create the Migration Task, the original data on the destination ECS instance is cleared. The data on the source server is not affected. If the ECS instance contains important data, this migration method is not recommended.
Go to the SMC console - Agentless Migration of VMware VMs page.
Find the migration source that you want to manage and click Start Migration in the Actions column.
Configure the parameters and click Start Migration.
Configure basic parameters.
Parameter
Description
Destination Type
Select the destination type based on your migration scenario:
ECS Image
Convert the existing source server into an ECS custom image, and then use that custom image to create a new ECS instance to complete the migration.
The following table describes the configuration items:
Destination Region: The Alibaba Cloud region to which you want to migrate your source server. This parameter is required. For more information about regions, see Regions and zones.
Image Name Prefix: The name of the destination Alibaba Cloud custom image that SMC generates for the migration source.
ECS instance
Migrate the source server directly to a purchased ECS instance. The storage, operating system, and other configurations of the source server and the purchased ECS instance must be compatible.
The following table describes the configuration items:
Destination Region: The Alibaba Cloud region to which you want to migrate your source server. This parameter is required. For more information about regions, see Regions and zones.
Destination Instance: Select an ECS instance as the destination instance.
Execution Method
Select an execution mode for the Migration Task:
Migrate Now: Starts the migration immediately after creating the migration task. Migrate Now is selected by default.
Schedule Migration: Creates a migration task that automatically starts at a set time.
NoteThe earliest scheduled execution time can be set to 10 minutes from the current time.
Create Only: Creates only a migration task. You must later manually start the migration task by clicking Start Migration in the Actions column.
Automatic Incremental Synchronization
Specifies whether the migration task automatically synchronizes incremental data from the source server to Alibaba Cloud. By default, automatic incremental synchronization is disabled.
NoteThis feature is not supported if you select ECS Instance as the destination.
If you enable this switch, you need to set the following configuration items:
Sync Repeat Frequency: The time interval at which the incremental migration task is automatically executed periodically.
Max Image Retention: The maximum number of images that the incremental migration task retains by default.
The Migration Task will run periodically and synchronize incremental data to Alibaba Cloud. For more information about best practices for incremental migration, see Agentless incremental migration for VMware VMs.
Network Type
Select the network to use for transferring migration data to the intermediate instance. By default, public network transmission is used. The intermediate instance is created in the selected virtual private cloud (VPC) and vSwitch, so it is assigned a public IP address.
Public Network Transmission (Default)
Migration data is transferred to the intermediate instance over the public network. This mode requires the source server to have public network access. As needed, choose whether to specify a VPC and a vSwitch.
Specify a VPC and vSwitch: The migration task creates an intermediate instance in your specified VPC and vSwitch.
Do not specify a VPC and vSwitch: The migration task creates an intermediate instance in a system-generated VPC and vSwitch.
Private Network Transmission
Migration data is transferred to the intermediate instance over the VPC's internal network. This mode requires you to connect the source server to the Alibaba Cloud VPC and specify a VPC and vSwitch.
NoteIf you can directly access a VPC in an Alibaba Cloud region from your on-premises data center, VM environment, or cloud host, we recommend using this migration method. Using the internal network provides faster and more stable data transmission than the public network, improving migration efficiency. You can connect the source server to the cloud VPC using a VPN Gateway, Express Connect circuit, physical connection, or Smart Access Gateway. For more information, see Connect a VPC to an on-premises data center or another cloud.
Destination Instance IPv4 Private Address
To change the private IP address of the destination instance, you can manually specify a private IP address. This parameter appears only when Destination Type is set to ECS Instance.
Keep Unchanged: By default, the migration IP address of the destination instance remains unchanged.
Manually Specify: Allows you to enter an address within the available IP CIDR block of the vSwitch where the destination instance is located. When the migration source's IP address is in the vSwitch's CIDR block, you can change the destination instance's IP address to the migration source's IP address.
When the destination instance's CIDR block is the same as the migration source's: Directly enter the private IP address of the migration source.
When the destination instance's CIDR block is different from the migration source's: You first need to change the VPC of the destination instance so that their CIDR blocks are the same, and then enter the private IP address of the migration source.
Configure the disk parameters. The following table describes the parameters.
Parameter
Description
Destination Disk Size (GiB)
Set the disk structure for the destination ECS server. Configure the parameters based on your business needs.
ImportantAgentless migration for VMware does not support disk shrinking. To shrink disks, switch to an agent-based migration method.
System disk
The size of the system disk for the destination Alibaba Cloud ECS server, in GiB. The value must be in the range of 20 to 2,048. The destination system disk size must be greater than the source system disk size. For example, if the source system disk size is 400 GiB, the destination system disk size must be greater than 400 GiB.
Data disk
Data Disk <N>: The size of the data disk for the destination Alibaba Cloud ECS server after migration, in GiB. The value must be in the range of 20 to 32,768.
The variable
<N>represents the data disk number.The destination data disk size must be greater than the source data disk size. For example, if the source data disk size is 500 GiB, the destination data disk size must be greater than 500 GiB.
NoteIf your migration source does not have a data disk, or if the data disk is not mounted, the Data Disk configuration item does not appear. For more information, see Why is the Data Disk configuration item not displayed on the Create Migration Task page?.
(Optional) To set advanced parameters such as network mode and compression ratio, click Advanced Settings. The following table describes these parameters.
Parameter
Description
Migration Task Name
The name of the Migration Task.
Task Description
Enter a description for the Migration Task.
Transmission Speed Limit
The transfer speed limit restricts the actual network transfer speed, in Mbps. If the Compression Ratio is set to a value greater than 0, the actual network transfer speed (the speed of compressed data transfer) will be less than the speed displayed in the Real-time Migration Status.
Compression Ratio
The level of data compression during migration. Set the compression ratio based on your actual needs.
In environments with limited bandwidth, using a high compression ratio can increase data transfer speed.
In environments with very high bandwidth, we recommend not compressing data to reduce the CPU resource consumption on the source server.
The value ranges from 0 to 10. The default is 7. A value of 0 means no data compression.
Checksum Verification
Disabled by default. Enabling it enhances data consistency verification but may reduce transfer speed.
SSL Encrypted Transmission
The default is Auto Select. Using Secure Sockets Layer (SSL) encryption for data transmission can improve data security and ensure data integrity.
License Type
Select the license type.
Alibaba Cloud (Default): Currently only supports Microsoft Windows Server licenses. When you create an ECS instance from the image in Hong Kong (China) or other regions outside China, you will be charged an image license fee, and the license will be automatically activated. The specific fee is subject to the information displayed when creating the instance.
Bring Your Own License: Bring Your Own License (BYOL) migration to the cloud currently includes Microsoft, Red Hat Enterprise Linux, and SUSE Linux Enterprise Server. When you create an ECS instance from the image after migration, you will not be charged an image license fee. Please use your own license for activation.
NoteIf you have already created an ECS instance, Alibaba Cloud supports quickly purchasing software licenses such as Red Hat Enterprise Linux and SUSE Linux Enterprise Server for the specified ECS instance. For more information, see Purchase a software license for an ECS instance.
Transmission Mode
Automatic: Default. This mode selects the best available transmission mode.
LAN: This mode uses Local Area Network (LAN) transmission. It requires that the VMware agentless connector VM can access the ESXi host of the source VM over the LAN.
LAN-Free: This mode uses storage network transmission. It requires that the VMware agentless connector VM and the source VM are on the same ESXi host.
Image Check
The image detection feature mainly checks whether an image is valid and whether it can be used to create a fully functional ECS instance. You can use the image detection feature when creating server migration and VMware agentless migration tasks.
Image detection helps you quickly identify potential problems with the image or instance after migration and provides repair solutions to make it compliant with Alibaba Cloud standards, improving the success rate of instance startup.
For more information, see Configure image detection.
Tags
Bind tag key-value pairs to the migration task for easy querying and management. For more information, see Use tags to manage migration sources and tasks and Implement fine-grained permission management using tags.
NoteA single migration task can be bound with up to 20 tags.
Intermediate Instance Type
You can select an intermediate instance type based on your actual needs. This parameter appears only when Destination Type is set to ECS Image.
If you specify this parameter, the system will use this instance type to create the intermediate instance. If this instance type is out of stock, the migration task creation will fail.
If you do not select an intermediate instance type, the system will select an instance type to create the intermediate instance.
ImportantTo avoid migration errors, do not stop, start, restart, or release the intermediate instance during the migration process. After the migration is complete, the instance is automatically released.
Upload Diagnostic Logs
Automatically upload SMC client logs to the SMC server-side for error diagnosis and analysis, which helps locate problems when migration errors occur. This feature is enabled by default.
SMC client logs are typically stored in the
/root/smc/Logsdirectory.
In the message that appears, read the migration notes and click Got It.
On the Agentless Migration of VMware VMs page, monitor the real-time status of the migration.
The time required for data transfer depends on factors such as the source data size and network bandwidth. Wait for the Migration Task to complete.
While the Migration Task status is Synchronizing, you can click Pause Migration Task in the Actions column to pause the task.
(Optional) View migration details.
In the Source ID/Name column for the migration source, click the source ID to view the migration details.
Verify migration results
If you set Destination Type to ECS Image:
After the migration is successful, a custom Alibaba Cloud image is created. You can scroll to the right and in the Migration Deliverable column, click View Report to view the image detection results. For more information, see View image detection results.
(Recommended) Manually verify the migration result
In the Actions column, click Create Instance. You are redirected to the instance creation page in the ECS console with the custom image pre-selected. For more information, see Create an instance using a custom image or a shared image.
Automatically verify the migration result
NoteTo use this feature, you need to install the Cloud Assistant plugin on the instance, and the instance's operating system version must support the plugin. For more information, see Install Cloud Assistant Agent.
This feature uses the Alibaba Cloud-provided OOS template
ACS-SMC-CreateAndVerifyInstanceto automatically verify whether an ECS instance can be created from the image generated by the migration task and start as expected.In the Actions column, click Verify Migration Result.
In the dialog box that appears, review the verification process and click Verify Now.
You can also click Customize Verification Script Parameters to manually configure verification parameters.
View the verification result in the Verify Migration Result column.
Verification Passed: The migration is valid. You can click Details to view the verification details.
Verification Not Completed: Indicates that the migration result is abnormal. You can click View Reason to find the cause of the error and troubleshoot the problem.
You can also click
in the Actions column and then click Go to OOS to View Historical Verifications to view the execution history of the OOS template.
If you set Destination Type to ECS Instance, you can click View Destination Instance in the Actions column to view the details of the destination ECS instance.
After you migrate the server, perform the following operations to ensure that your business runs as expected:
Perform data validation and verification to ensure data integrity and correctness. For more information, see How do I check the system after migrating a Linux server? or How do I check the system after migrating a Windows server?.
If applications and services on the source server are not set to auto-start, you must manually start them after the migration.
The IP address changes after the migration. If your business involves IP address configurations, you must modify the domain name resolution, ICP filing, and other settings after the migration.
If a domain name is mapped to the source server, map the domain name to the public IP address of the destination server. For more information, see Add a DNS record.
If you want to keep the original private IP address, you can manually modify it after the migration is complete.
Migrate to an ECS Image: You can modify the private IP address when you create an ECS instance. For more information, see Specify the primary private IPv4 address for the primary NIC when creating an ECS instance.
Migrate to an ECS Instance: If you do not modify the private IPv4 address in the advanced configuration during the migration settings step, you can modify it after the migration is complete. For more information, see Modify the primary private IPv4 address of the primary NIC for an existing instance.
Clean up resources
Migrate to an ECS image
During the migration, SMC creates a temporary pay-as-you-go intermediate instance named No_Delete_SMC_Transition_Instance in your destination Alibaba Cloud account to assist with the migration. Whether you need to manually clean up the instance depends on the migration result:
Migration successful: The intermediate instance is automatically released. You do not need to clean it up manually.
Migration error: The intermediate instance persists with the migration task and incurs charges. You can release it in one of the following ways to avoid unnecessary charges:
If you no longer need this migration task, click the source ID, and then in the Actions column, click Cancel Migration. This action deletes the migration task and automatically cleans up the intermediate instance.
Manually release the intermediate instance.
Migrate to an ECS instance
During the migration, SMC creates a temporary pay-as-you-go intermediate disk named SMC_Temp_Disk under the destination instance to assist with the migration. Whether you need to manually clean up this intermediate disk depends on the migration result:
Migration successful: The intermediate disk is automatically released. You do not need to clean it up manually.
Migration error: The intermediate disk persists with the migration task and incurs charges. You can release it in one of the following ways to avoid unnecessary charges:
If you have confirmed that a migration task is no longer needed, click its source ID. In the Actions column for the task, click Cancel Migration. This action deletes the migration task and automatically cleans up the intermediate disk.
Manually release the intermediate disk.
Related documentation
Incremental migration
If you need to migrate incremental data multiple times, you can perform multiple incremental migrations at custom intervals after the first full migration completes. This process synchronizes incremental data from your source server to Alibaba Cloud, reducing business downtime and shortening the final cutover time. For more information, see Agentless incremental migration for VMware VMs.
ECS server migration guide
Alibaba Cloud provides various methods for migrating servers to the cloud and within the cloud. Examples include migrating on-premises physical machines to Alibaba Cloud, migrating Tencent Cloud servers to Alibaba Cloud, and migrating ECS instances between different accounts on Alibaba Cloud. You can choose the migration method that best fits your business scenario. For more information, see ECS server migration guide.
SMC also provides the following migration capabilities:
The SMC client is a migration tool from Alibaba Cloud that runs on the source server during migration. For more information, see SMC client user guide.