This topic describes system events that require instance migration due to infrastructure upgrades and provides recommended migration solutions.
Event details
To continuously improve the performance and stability of ECS, Alibaba Cloud is upgrading the physical infrastructure in some legacy regions and zones. To prevent these upgrades from affecting your instances, Alibaba Cloud will notify you by phone, text message, email, and internal message. If you receive such a notification, follow the provided instructions to migrate your instance.
The corresponding system event code isSystemUpgrade.Migrate. The migration process is as follows:
You receive a notification to migrate your instance.
You migrate the instance at your chosen time.
Migration solutions and considerations
If you encounter issues during the instance migration, refer to the FAQ section in this topic or contact your account manager.
Use one of the following recommended solutions to migrate your instance at a convenient time:
Scenario | Solution and considerations |
Migration for instances that do not use legacy images. |
|
Migration for instances that use legacy images (such as Windows Server 2003, CentOS 5.8, or earlier). | After you migrate an instance that uses a legacy image, such as Windows Server 2003 or CentOS 5.8, issues such as kernel panics, blue screens, or INACCESSIBLE_BOOT_DEVICE errors might occur. For solutions, see Troubleshoot post-migration instance downtime. |
View instance migration events
Go to ECS console - Events.
View the instance migration events for infrastructure upgrades.
If a number is displayed on the Instance migration for infrastructure upgrades tab, it indicates you have pending events. The following figure shows an example.
Select a migration solution based on your business requirements.
For information about how to choose a migration solution, see Migration solutions and considerations.
Next steps
To keep the public IP address after the migration, see Convert the static public IP address of an ECS instance in a VPC to an EIP.
To modify the private IP address in the VPC after the migration, see Modify the private IP address of an instance.
FAQ
Does the migration change the security groups?
No. The security groups remain unchanged.
Do IP addresses change after migration?
Public IP address: The public IP address remains unchanged.
ImportantECS instances in a VPC do not have public network interface controllers and access the internet through NAT. Only the private IP address is visible within the instance's operating system. If your application requires the public IP address to be visible in the OS, carefully evaluate whether to migrate.
Private IP address: You can choose whether to retain the private IP address. You can also modify the private IP address after the migration is complete. For more information, see Modify the private IP address of an instance.
Migration plan execution and duration
The process takes about 15 minutes, from stopping the source ECS instance to starting the migrated ECS instance.
When the migrated ECS instance starts, its compute and network resources are available, and you can use your services normally.
For a cross-zone migration, disk data transfer continues after the instance starts. It typically takes about 4 hours to migrate 100 GiB of disk data. During this period, disk I/O performance is temporarily reduced, and you cannot manage snapshots or disks. Your services remain available during the data migration process.
Impact on system settings
No. Services and data in the system remain unchanged.
For more information about migration impacts, see Migration impacts.