CentOS has announced the end of life (EOL) for CentOS Linux including CentOS 7 and CentOS 8. If you need future technical support for your operating system, you must migrate your CentOS operating system to another Linux operating system that provides long-term support (LTS). This topic describes how to use Server Migration Center (SMC) to migrate the CentOS 7 and CentOS 8 operating systems to Alibaba Cloud Linux and Anolis OS.

Prerequisites

  • The preparations for the migration are complete. For more information, see Before you begin.
  • The information of the source operating system is imported to the SMC console. For more information, see Step 1: Import the information of a migration source.
  • The migration source is in the Available state. If the migration source is not in the Available state, you cannot create a migration task for the migration source. For more information about how to restore a migration source to the Available state, see the "What can I do if I cannot create a migration task because the migration source is not in the Active state?" section of the SMC FAQ topic.

Scenarios

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.
Notice The operating system to be migrated must be the operating system of an Elastic Compute Service (ECS) instance within the current Alibaba Cloud account.

Usage notes

  • During the migration process, the following operations need to be performed on the ECS instance: create snapshots for basic disks, reinstall software packages, stop the ECS instance, create a custom image from a system disk snapshot, replace the system disk, and start the ECS instance. We recommend that you back up important data and plan a proper migration time to prevent the preceding operations from affecting your business.
  • During the migration process, do not stop, restart, or release the ECS instance in manual mode or by using O&M scripts.
  • You are charged for snapshots that are created during the migration process in pay-as-you-go mode. For more information, see Snapshots.

Procedure

  1. Log on to the SMC console.
  2. In the left-side navigation pane, click Migration Sources.
  3. Find the source operating system migration source, and click Create Migration Job in the Actions column.
    You can obtain the ID of the migration source from the SMC client. The following figure shows an example. Then, you can use the ID to find the migration source in the SMC console. For more information, see the "How do I find a migration source in the SMC console?" section of the SMC FAQ topic. Obtain the ID of the migration source
  4. In the Create Migration Job dialog box, set the parameters to create an operating system migration task.
    Parameter description:
    • Migration Job Type: Select OS Migration.
    • Current operating system: By default, the current operating system is displayed and cannot be modified. Example: CentOS8.
    • Target operating system: Select the operating system to which you want to migrate the source operating system from the drop-down list. Example: Alibaba Cloud Linux 3.
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  5. Click Create.
  6. On the Migration Jobs page, wait until the migration task is complete.
    • If the migration task enters the Finished state, the migration is successful. daasda5862You can click View Destination Instance in the Actions column that corresponds to the migration task. On the tab of the instance details, you can view that the source operating system is migrated to the destination operating system.
    • If the migration task enters the InError state, the migration fails. You can check the logs to troubleshoot the failure. Then, restart the migration task. For information about common errors and solutions, see SMC FAQ. If you want to roll back the system disk on which the source operating system is installed, you can use the snapshots that are automatically created for the system disk. To roll back the system disk, perform the following steps:
      1. Log on to the ECS console.
      2. In the left-side navigation pane, choose Storage & Snapshots > Snapshots.
      3. On the Disk Snapshots tab, find the snapshot that you want to use to roll back the system disk, and click Roll Back Disk in the Actions column.
      4. In the Roll Back Disk message, click OK.