Migrate servers with an agent-Server Migration Center(SMC)-阿里云帮助中心

Migration scenarios

Migrate from on-premises data centers to Alibaba Cloud
Migrate from on-premises virtual machines, such as VMware, VirtualBox, Xen, KVM, and Hyper-V, to Alibaba Cloud
Migrate from other cloud providers, such as Amazon Web Services (AWS), Microsoft Azure, Google Cloud Platform (GCP), Tencent Cloud, UCloud, China Telecom Cloud, and QingCloud, to Alibaba Cloud
Migrate servers across different Alibaba Cloud accounts or regions

Features

Platform-independent. Supports mainstream operating systems and environments.
Supports live migration without interrupting source server services.
No installation required — download, decompress, and run.
Data encrypted with 2048-bit RSA during transmission by default.
Supports resumable transfers and data compression.
Supports incremental migration to reduce downtime and cutover time.

How it works

You can migrate a source server to a custom image (then create an ECS instance from it), or migrate directly to a target ECS instance.

How migration to a custom image works

The migration process:

Download and run the SMC client on the source server. If you import the migration source from the command line or console, the system handles this automatically.
The SMC client registers the source server and reports its information to the SMC service through the SMC service domain name.
The SMC service creates a temporary intermediate instance and opens inbound ports 8080 and 8703 in the security group.
The SMC client connects to the intermediate instance on port 8080 and then transfers disk data to the data disks of the intermediate instance through port 8703.
The SMC service creates snapshots from the disks of the intermediate instance and then creates an image from the snapshots.

How migration to a target instance works

The migration process:

Download and run the SMC client on the source server. If you import the migration source from the command line or console, the system handles this automatically.
The SMC client registers the source server and reports its information to the SMC service through the SMC service domain name.
The SMC service connects to the target instance, creates and attaches a temporary intermediate disk, and opens inbound ports 8080 and 8703 in the security group.
The SMC client connects to the target instance on port 8080 and then transfers disk data to the data disks of the target instance through port 8703.
The SMC service creates snapshots from the disks of the target instance and then creates an image from the snapshots.
The SMC service replaces the system disk of the target instance with the new image.

Supported network migration modes:

SMC supports migration over public or private networks. The source server must reach the intermediate or target instance.

Public network transfer (default): The source server needs public network access. Open inbound ports 8080 and 8703 in the security group. Data transfers to the intermediate instance over the public network.
Private network transfer: Connect the source server to an Alibaba Cloud VPC and specify the VPC and vSwitch for migration. Data transfers over the VPC's private network — faster and more stable than public transfer. Use VPN Gateway, Express Connect, or Smart Access Gateway to connect your source server to the VPC. Connect a VPC to a data center or another cloud. Private network transfer migration.

Limits

Operating system limits

The following table lists the supported operating systems for server migration.

Windows	Linux
Windows Server 2003 Windows Server 2008 Windows Server 2012 Windows Server 2016 Windows Server 2019 Windows Server 2022 Important Windows Server 2003 and 2008 cannot be activated after migration. Upgrade the OS afterward. Windows Server operating systems.	CentOS 5/6/7/8 Red Hat 5/6/7/8 Ubuntu 10/12/14/16/17/18/20/22/24 Debian 7/8/9/10/11 OpenSUSE 13/42/15 SUSE 11/12/15 Gentoo 13.0 Alibaba Cloud Linux 2/3 Oracle Linux 5/6/7/8 Amazon Linux 2014 and later

Data migration limits

Source server operating system	Data migration limits
Windows	Some disk partition structures, such as dynamic disk partitions and extended disk partitions, cannot be copied. Unsupported partition structures are rebuilt as standard partitions. Volume Shadow Snapshots cannot be migrated.
Linux	Some disk partition structures, such as LVM partitions and extended disk partitions, cannot be copied. Unsupported partition structures are rebuilt as standard partitions. SWAP partitions cannot be copied and must be reconfigured after migration. Some non-mainstream file system formats cannot be copied. Unsupported file systems are rebuilt in a mainstream format such as ext2, ext3, or ext4. When block replication is not supported, virtual memory, cache, system snapshot files, some software configurations (cloud-init, network services), and docker folder data are not migrated by default. Check the filter configuration file `rsync_excludes_linux.txt` in the SMC client folder for the full exclusion list. Note The path to the default filter configuration file varies based on the SMC client installation folder. If you automatically import a migration source from the console or import a migration source from the command line, the path to the filter configuration file is `/smc/go2aliyun_client2.X.X_linux_x86_64/Excludes/rsync_excludes_linux.txt`. If you import the migration source using the SMC client, the path of the filter configuration file depends on the specific installation path.

Limits on the number of migration sources and tasks

Limitations	Limit for regular users	How to request an exception
Total number of migration sources that can be registered per Alibaba Cloud account	1,000	Submit a ticket
Total number of migration tasks that can be created per Alibaba Cloud account	1,000	Submit a ticket
Number of concurrent migration tasks that can be run per Alibaba Cloud account	50	Submit a ticket

Disk size limits

SMC limits the size of disks that can be migrated. If a disk exceeds the capacity limit, use other methods such as `cp` or `sftp` to transfer data.

Windows server
- System disk: The maximum capacity is 2 TiB.
- Data disk: The maximum capacity is 10 TiB.
Linux server:
- System disk: The maximum capacity is 2 TiB.
- Data disk: The maximum capacity is 32 TiB.
  
  If the data volume on a data disk exceeds 500 GiB, block replication is not supported for migration.

Start migration

To start a server migration, follow the Migration guide.