This topic provides answers to some frequently asked questions (FAQ) about Server Migration Center (SMC).

How am I charged for SMC?

SMC is a free service. However, when you use SMC to migrate servers, you are charged for the Elastic Compute Service (ECS) resources that are consumed during the migration process. ECS resources include intermediate instances, snapshots, and system disks and data disks that are attached to the intermediate instances. For more information, see Billing.

How do I find a migration source in the SMC console?

To find a migration source, perform the following steps:
  1. Log on to the SMC console.
  2. In the left-side navigation pane, click Migration Sources.
  3. On the Migration Sources page, click the search box and select a search item from the drop-down list.

    Search items include Migration Source Name, Migration Source ID, Status, and Last Migration Job ID. All search queries return the results that exactly match the search items.

  4. Enter a value for the selected search item and press the Enter key.

What do I do if I want to reimport a migration source?

You must delete the migration source, restart the SMC client, and then reimport the migration source. If the migration source is associated with a migration task, you must delete the migration task before you delete the migration source.

Why am I unable to delete a migration source?

You cannot delete a migration source if the migration source is associated with an ongoing migration task. You must stop and delete the migration task before you delete the migration source.

Why is an ECS instance not displayed on the ECS Instance tab after I import the ECS instance as a migration source?

  • If the network type of your ECS instance is classic network, the migration source is displayed on the Physical Server/VM/Third-party Cloud Server tab by default.
  • If the network type of your ECS instance is Virtual Private Cloud (VPC), the migration source is displayed on the ECS Instance tab by default.

What scenarios can I use SMC for?

You can use SMC to migrate various types of servers to ECS, such as physical servers, VMs, and third-party cloud servers. These servers can run on Windows or Linux. For more information, see What is SMC?

How do I migrate a server?

For more information about how to migrate a server, see Migration process.

How do I estimate the time required for a migration task? How do I test the data transfer speed?

You can estimate the time required for a migration task based on the migration period. The migration period is divided into three phases: pre-migration, migration, and post-migration. The migration period is proportional to the number of servers that you want to migrate and the volume of data. We recommend that you perform a test migration to estimate the time required for a migration task.

For more information, see Estimate the time required for migration and test the data transfer speed.

How do I exclude files or directories from a migration task?

To exclude files or directories from a migration task, add the file paths or directories to the following configuration files. The configuration files reside in the Excludes directory of the SMC client.
Important
  • If you enable the block replication feature, you cannot exclude files or directories from the migration task.
  • If a configuration file is lost or deleted by accident, you can create another one.
  • System disk configuration file:
    • Windows: rsync_excludes_win.txt.
    • Linux: rsync_excludes_linux.txt.
  • Data disk configuration file:
    • Windows: The configuration file is named with the suffix disk[Disk index number] added to the name of the system disk configuration file, such as rsync_excludes_win_disk1.txt.
    • Linux: The configuration file is named with the suffix disk[Disk index number] added to the name of the system disk configuration file, such as rsync_excludes_linux_disk1.txt.
Examples:
  • Example 1: Exclude files or directories from the migration of a Windows server
    • System disk:
      • Files or directories that you want to exclude: 
        C:\MyDirs\Docs\Words
C:\MyDirs\Docs\Excels\Report1.txt
      • Add the following information to the rsync_excludes_win.txt file: 
        /MyDirs/Docs/Words/
/MyDirs/Docs/Excels/Report1.txt
    • Data disk:
      • Files or directories that you want to exclude: 
        D:\MyDirs2\Docs2\Words2
D:\MyDirs2\Docs2\Excels\Report2.txt
      • Add the following information to the rsync_excludes_win_disk1.txt file: 
        /MyDirs2/Docs2/Words2/
/MyDirs2/Docs2/Excels2/Report2.txt
      Note
      To exclude a Windows directory, perform the following operations:
      • Remove the prefix of the directory (scr_path). In the preceding example, D: is removed.
      • Replace \ with /.
  • Example 2: Exclude files or directories from the migration of a Linux server
    • System disk (root directory/):
      • Files or directories that you want to exclude: 
        /var/mydirs/docs/words
/var/mydirs/docs/excels/report1.txt
      • Add the following information to the rsync_excludes_linux.txt file: 
        /var/mydirs/docs/words/
/var/mydirs/docs/excels/report1.txt
    • Data disk:
      • Files or directories that you want to exclude: 
        /mnt/disk1/mydirs2/docs2/words2
/mnt/disk1/mydirs2/docs2/excels2/report2.txt
      • Add the following information to the rsync_excludes_linux_disk1.txt file: 
        /mydirs2/docs2/words2/
/mydirs2/docs2/excels2/report2.txt
      Note To exclude a Linux directory, you must remove the prefix of the directory (scr_path). In the preceding example, /mnt/disk1 is removed.

Is BYOL supported when I migrate servers by using SMC?

Yes, SMC supports bring your own license (BYOL). BYOL licenses are used in the following scenarios:
  • Microsoft
    Microsoft BYOL licenses are used in the following scenarios:
    • BYOL implemented by using Software Assurance (SA)

      BYOL can be implemented for software programs such as SQL Server and SharePoint that support License Mobility when ECS instances are created.

    • Windows

      Windows client access licenses (CALs) do not support License Mobility. Therefore, existing Windows licenses cannot be used within shared hardware environments. You must deploy a Windows operating system in a dedicated physical environment, which can be an Alibaba Cloud dedicated host or an ECS bare metal instance. For more information, see What is DDH? and Overview.

      Alibaba Cloud does not provide Key Management Service (KMS), Windows Server Update Services (WSUS), or software technical support for these types of ECS instances. You can contact Microsoft for software technical support.

    • No SA or no support for BYOL implemented by using SA

      This scenario is similar to the scenario where a Windows operating system is used. You can reuse software licenses that you have purchased and downloaded, and deploy software programs in a dedicated hardware environment.

  • Red Hat

    Red Hat provides the Cloud Access program. If you migrate Red Hat subscriptions to Alibaba Cloud by using the bring your own subscription (BYOS) method, you can register with Red Hat Cloud Access. For more information, see Step 1: Enroll in the Red Hat Cloud Access program

Does SMC support resumable data transfer?

Yes, SMC supports resumable data transfer. If data transfer is interrupted, you can restart the SMC client and the migration task to resume migration.

Does SMC support incremental data migration?

Yes, SMC supports incremental data migration. For more information, see Migrate incremental data from a source server.

How do I check my system after I migrate a Windows server?

After you migrate your Windows server, you must perform the following steps when you start the created instance for the first time:
  1. Check whether the system disk data is complete.
  2. If a data disk is missing, go to the Disk Management utility to check whether the drive letter is missing.
  3. Check whether the hostname is valid and the network is connected.
  4. Check whether other system services are running as expected.

How do I check my system after I migrate a Linux server?

After you migrate your Linux server, you must perform the following steps when you start the created instance for the first time:
  1. Check whether the system disk data is complete.
  2. If data disks exist, you must attach the data disks to the instance. For more information, see Attach a data disk.
  3. Check whether the hostname is valid and the network is connected.
  4. Check whether other system services are running as expected.

How do I migrate a server again?

To migrate a server again, create a migration task for the server, and then start the task.

What do I do after a migration task is complete and a custom image is generated?

We recommend that you use the custom image to create a pay-as-you-go instance, and then check whether the system is running as expected. After you confirm that the custom image is available, select instance types that meet your business requirements and create one or more ECS instances. For more information, see Overview of instance families and Create an instance by using the wizard.

What happens after a migration task is complete?

After a migration task is complete, SMC generates one of the following migration results based on the destination image type:
  • If the destination image type is ECS Image, an ECS image is generated. You can use the ECS image to create an ECS instance.
  • If the destination image type is ECS Instance, the source server is directly migrated to the destination ECS instance.
  • If the destination image type is Container Image, a container image is generated. You can use the container image to deploy applications.

How do I migrate a source server to Alibaba Cloud?

SMC allows you to migrate servers that run various versions of Windows or Linux operating systems to Alibaba Cloud. Source servers can be those deployed in data centers, on-premises VMs, or those on other cloud platforms. For more information, see Migrate servers to Alibaba Cloud.

How do I migrate data between Alibaba Cloud ECS instances?

If you want to migrate data between Alibaba Cloud ECS instances, we recommend that you use the Copy Image and Share Image features. For more information, see Copy an image and Share a custom image. If these two features cannot meet your business requirements, you can use SMC to migrate data. For more information, see Migrate servers between ECS instances.

What do I do if a migration task is interrupted or fails?

If a migration task is interrupted or fails, use the following troubleshooting methods:

  • If the SMC client exits due to an exception or the migration process stalls, restart the SMC client and the migration task to resume the migration.
  • If the migration task is in the InError state, check the log file of the migration task in the SMC console to identify the cause of error.

    If the issue persists, we recommend that you join the SMC support group on DingTalk. For more information, see Contact us.

How do I fix the IP address of an intermediate instance?

You can apply for an elastic IP address (EIP) and then associate the EIP with the intermediate instance. For more information, see Quick start.

What public endpoints and ports does my source server need to access?

A source server must access the following endpoint and ports:
  • SMC endpoint: https://smc.aliyuncs.com:443.
  • Ports 8080 and 8703 of the intermediate instance. If the migration is performed over a VPC, the source server must also access the private IP address of the intermediate instance.
Note You do not need to enable inbound ports for the source server. However, you must make sure that the server can access the preceding endpoint and ports.

What Windows Server licenses does Alibaba Cloud support?

Alibaba Cloud supports licenses for Windows Server 2012, 2016, 2019, and 2022. Microsoft no longer supports licenses for Windows Server 2008 and earlier versions. To migrate servers that run other versions of Windows operating systems to Alibaba Cloud, you must apply for License Mobility. For more information, see Apply for License Mobility

SMC supports BYOL. You can use the following method to activate a Windows server:

How do I migrate a source server to Container Registry?

SMC allows you to migrate source servers to Container Registry. You can use SMC to migrate containerized applications to Container Registry in a cost-effective way. For more information, see Migrate source servers to Container Registry.

How do I migrate a source server to an ECS instance?

SMC can be used to migrate source servers to ECS instances. After you purchase an ECS instance, you can migrate your source server to the ECS instance. For more information, see Migrate servers to ECS instances.

What do I do if I release an intermediate instance by accident?

If you release an intermediate instance by accident, delete the current migration task, create a migration task for the migration source, and then start the migration task. If the issue persists, you can submit a ticket.

What do I need to know about intermediate instances?

You need to know the following information about intermediate instances:
  • SMC creates, starts, stops, and releases an intermediate instance named No_Delete_SMC_Transition_Instance during a migration process. To ensure a smooth migration, do not modify the status of the intermediate instance.
  • The default security group of the intermediate instance allows access to ports 8080 and 8703. These ports are the migration service ports of the intermediate instance. Do not modify or delete the security group.
  • After the migration is complete, the intermediate instance is automatically released. If the migration fails, you must manually release the instance. For more information, see Release an instance.

How does SMC create an intermediate instance?

SMC attempts to create an intermediate instance based on the following specifications in sequence: The following part describes the specifications of intermediate instances:
  • x86 architecture
    • 1 vCPU 2 GiB
    • 1 vCPU 4 GiB
    • 2 vCPU 2 GiB
    • 2 vCPU 4 GiB
    • t6, burstable instance family
    • t5, burstable instance family
    • 2 vCPU 8 GiB
  • ARM64 architecture
    Instance typevCPUMemory (GiB)
    ecs.c6r.large24
    ecs.g6r.large28
    ecs.c6r.xlarge48
    ecs.g6r.xlarge416
    ecs.c6r.2xlarge816
    ecs.g6r.2xlarge832
    ecs.c6r.4xlarge1632

If the preceding instance specifications are unavailable, SMC selects other cost-effective instance specifications.

What do I need to know about block replication?

You need to know the following information about block replication:
  • If you migrate a Windows server, you must enable block replication.
  • To ensure the transmission efficiency, integrity, and consistency of partition data, we recommend that you enable block replication.
  • If you enable the block replication feature, you cannot exclude files or directories from the migration.

What do I do if I am unable to create a migration task because the migration source is not in the Active state?

Restore the migration source to the Active state, and then create a migration task. To fix the issue, perform the following operations:
  • If the migration source is in the Inactive state,

    the migration source is disconnected from the SMC console. You must restart the SMC client and wait until the migration is complete. For more information, see Import the information about a migration source by using the SMC client.

  • If the migration source is in the InError state, you must check the console logs. You must also check the client logs in the Logs folder and the error messages on the client UI. Resolve the error based on the logs. You can also use the error codes and troubleshooting methods in this topic for reference. If the issue persists, contact Alibaba Cloud technical support. For more information, see Contact us.

How do I install rsync?

To install rsync, run one of the following commands based on the operating system of your source server:
  • CentOS: yum -y install rsync.
  • Ubuntu: apt-get -y install rsync.
  • Debian: apt-get -y install rsync.
  • SUSE: zypper install rsync.
  • Other operating systems: See the installation documentation on the official website.

How do I disable SELinux?

To temporarily disable SELinux, run the setenforce 0 command. To permanently disable SELinux, open the configuration file in the /etc/selinux/config directory, and then set the SELINUX parameter to disabled.

Why are the data disk parameters of a migration source not displayed in the Create Migration Job dialog box? What do I do?

This issue occurs because your migration source is not configured with data disks or has a data disk that is not attached. If your migration source has no data disk or has a data disk that is not attached, the data disk parameters are not displayed in the Create Migration Job dialog box. To resolve this issue, perform the following steps:
  1. Attach a data disk.
  2. Restart the SMC client.
  3. Refresh the Migration Sources page in the SMC console, and open the Create Migration Job dialog box again.

Can I create a migration task for a migration source that has a running or failed migration task?

No, you cannot create a migration task for the migration source in this case. However, you can create a migration task after you perform the following operations:
  • If an existing migration task is in progress, stop and delete the migration task.
  • If an error occurs in an existing migration task, delete the migration task.

What is the validity period of a migration task? What happens after a migration task expires?

A migration task expires 30 days after it is created in the SMC console. The expiration time cannot be changed in the console. If you call the CreateReplicationJob operation to create a migration task, you can set a value for the validity period based on your business requirements. The validity period ranges from 7 to 90 days.

The validity period starts from the time at which the migration task is created. You can use the following two methods to process an expired migration task:
  • If the migration task is in the Running state, do not perform any operations on the migration task.
  • If the migration task is in the Ready, Stopped, or InError state, change the state of the migration task to Expired. SMC deletes the migration task seven days after the task expires.

What are the states of migration tasks? What do these states indicate?

The status of a migration task is divided into the following two types: The following figure shows the relationships between the status and business status of a migration task. job_status
Table 1. States of a migration task
StateDescriptionSupported operation
ReadyThe migration task is created but is not started. Start the migration job.
RunningThe migration task is in progress. A business state rather than the Running state is displayed in the Status column of the SMC console. For more information, see Business states of a migration task. Wait until the migration task is complete, or stop the migration task when it is in the Syncing state.
Note You cannot delete a migration task that is in the Running state.
StoppedThe migration task is stopped. Restart or delete the migration task.
InErrorThe migration task fails. Check the error message or migration logs on the SMC client or in the console to identify the cause and fix the issue. If the migration source is in the Inactive or InError state, the failure is caused by the SMC client. You must restart the client before you restart the migration task.
FinishedThe migration task is complete. Go to the Custom Images tab in the ECS console to view the image generated by SMC.
WaitingThe task is waiting to be run. This state is applicable only to incremental migration tasks. For more information, see Migrate incremental data from a source server. If the migration task is in the Waiting state, you can perform the following operations:
  • Use the image generated by the migration task to create an ECS instance.
  • Stop the migration task.
  • Delete the migration task.
  • Perform the incremental migration of source servers.
  • Modify the settings of automatic incremental migration. The settings include the interval at which the migration task is run and the maximum number of images that can be retained for the migration task.
ExpiredThe migration task has expired. Delete the migration task.
Note The valid duration of a migration task is 30 days. If a migration task expires, the state of the task changes to Expired but the task is retained for seven days. SMC deletes the migration task seven days after the task expires. For more information, see What is the validity period of a migration task? What happens after a migration task expires?.
DeletingThe migration task is being deleted. Wait until the migration task is deleted, or create another migration task for the migration source.
Note After a migration task is deleted, SMC releases the resources used during the migration process, such as the intermediate instance. This process may take a long time to complete.
Table 2. Business states of a migration task
Business stateDescriptionSupported operation
PreparingAfter you start a migration task, the state of the task changes to Preparing. None.
SyncingThe migration task is uploading data from the migration source. Stop the migration task.
ProcessingThe migration task is creating an image of the migration source. None.
CleaningThe intermediate instance is being released, and the migration task is almost complete. None.

What do I do if I cannot select a destination instance when I create a migration task?

Perform the following steps to troubleshoot the issue:
  1. If you perform migration across accounts, check whether the migration task is created by using the destination account.
  2. Check whether the destination region is valid.
  3. Check whether the source server and the destination instance run the same operating system. If the source server runs Windows, the destination instance must also run Windows. If the source server runs Linux, the destination instance must also run Linux.

I have a single Oracle database instance on a physical server. Do I need to migrate the entire server, including the operating system and database, or only the database to Alibaba Cloud? What are the advantages and disadvantages of the two methods?

You can migrate the entire server or only the database based on your business requirements. The two methods have the following advantages and disadvantages:
  • If you need only the Oracle database, we recommend that you migrate only the database. However, you may need to deploy the database in a new environment.
  • If you need both the database and its operating environment, we recommend that you migrate the entire server to Alibaba Cloud. However, if the server has a large volume of resources, the migration may require more time to be complete.

How do I install OpenSSH on a Windows server?

In this example, Windows 2016 is used. To install OpenSSH, perform the following steps:
  1. Download and decompress the OpenSSH-Win64.zip file to the specified directory, such as C:\OpenSSH-Win64.
  2. Open Windows PowerShell with administrator privileges and go to the directory in which the OpenSSH-Win64.zip file is decompressed. 
    cd \OpenSSH-Win64
    asda56
  3. Run the following command to install OpenSSH: 
    powershell.exe -ExecutionPolicy Bypass -File install-sshd.ps1
    PS C:\OpenSSH-Win64> powershell.exe -ExecutionPolicy Bypass -File install-sshd.ps1
  [*] C:\OpenSSH-Win64\moduli
Inheritance is removed from 'C:\OpenSSH-Win64\moduli'.
'BUILTIN\Users' now has Read access to 'C:\OpenSSH-Win64\moduli'.
      Repaired permissions

[SC] SetServiceObjectSecurity SUCCESS
[SC] ChangeServiceConfig2 SUCCESS
[SC] ChangeServiceConfig2 SUCCESS
sshd and ssh-agent services successfully installed
  4. Run the following commands to set up SSH: 
    cmd /c sc.exe config sshd start=auto
cmd /c sc.exe config ssh-agent start=auto
cmd /c net.exe start sshd
New-ItemProperty -Path "HKLM:\SOFTWARE\OpenSSH" -Name DefaultShell -Value "C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe" -PropertyType String -Force
New-ItemProperty -Path "HKLM:\SOFTWARE\OpenSSH" -Name DefaultShellCommandOption -Value "/c" -PropertyType String -Force
For more information, see Install Win32 OpenSSH.

Does the image generated by incremental migration contain the data of the source server at the beginning or end of the migration task?

The data that is migrated in an incremental migration task is the data of the source server at the start of the incremental migration task. The data generated by the source server during the incremental migration is migrated in the next incremental migration task.

Does the modification of synchronization interval for incremental migration take effect immediately?

No, the modification of synchronization interval for incremental migration does not take effect immediately. The modification takes effect when the next migration task starts.

Why do more disks exist after a Windows server is migrated to an image and an ECS instance is created from the image?

When you create a migration task, you must set the value of the disk size to an integer in units of GB. In most cases, the value that you specify is hundreds of MB larger than the system volume of the source server. If an extra drive letter exists after migration, you can use Disk Management to delete the drive letter.

How do I migrate an operating system?

CentOS has announced the end of life (EOL) for CentOS Linux versions including CentOS 7 and CentOS 8. If you need future technical support for your CentOS operating system, you must migrate your CentOS operating system to another Linux distribution with long-term support (LTS). For more information, see Migrate an operating system.

What operating system migration scenarios does SMC support?

SMC supports the following operating system migration scenarios:
  • Migrate CentOS 7 to Alibaba Cloud Linux 2 or Anolis OS 7.
  • Migrate CentOS 8 to Alibaba Cloud Linux 3 or Anolis OS 8.
Important
  • The operating system to be migrated must be the operating system of an ECS instance within the current Alibaba Cloud account.
  • Alibaba Cloud Linux 2 and 3 do not support GUIs. You can migrate your CentOS operating system with a GUI to Anolis OS.

What is VMware migration without agents?

SMC allows you to migrate VMware VMs without agents. This way, the migration does not intrude into the SMC client operating system or occupy the computing resources of the SMC client operating system. This can effectively eliminate the concerns of customers about server security and performance. For more information, see Migrate VMware VMs without agents.

What are the benefits of VMware migration without agents?

VMware migration without agents has the following benefits:
  • No resource consumption

    The SMC client does not run inside VMs. Therefore, the migration does not consume resources of VMs.

  • High migration efficiency

    You do not need to separately install an agent for each VM. This reduces the costs of labor and time.

  • High security

    No operations are performed within the operating system of a VM. This eliminates concerns of customers about security.

  • High compatibility

    The migration does not depend on the internal environment of the VM operating system. This improves the success rate of migration.