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  5. Automatically Recovering ECSs

Automatically Recovering ECSs

ECSs run on physical hosts. Although there are multiple mechanisms to ensure system reliability, error tolerance, and high availability, host hardware might be damaged or power failure might occur. If physical hosts cannot be powered on or restarted due to damage, CPU and memory data will lose, and the ECSs cannot recover through live migration.

The public platform provides automatic recovery to restart ECSs through cold migration, ensuring high availability and top-performing dynamic migration capability of ECSs. You can enable automatic recovery during or after ECS creation. Once a physical host accommodating ECSs breaks down, the ECSs with automatic recovery enabled automatically migrate to a functional host. This minimizes user service interruption. These ECSs will restart in this process.

Notes

  • Automatic recovery does not ensure user data consistency.
  • An ECS can be automatically recovered only if the host on which it is deployed becomes faulty. This function does not take effect if the fault is caused by the ECS itself.
  • An ECS can be automatically recovered only after the physical host on which it is deployed is shut down. If the physical host is not shut down due to a fault, for example, a memory fault, automatic recovery fails to take effect.
  • An ECS can be automatically recovered only once within 12 hours if the host on which it is deployed becomes faulty.
  • ECS automatic recovery may fail in the following scenarios:
    • No physical host is available for migration due to a system fault.
    • The target physical host does not have sufficient temporary capacity.
  • An ECS with any of the following resources cannot be automatically recovered:
    • Local disk
    • Passthrough FPGA card
    • Passthrough InfiniBand NIC

Procedure

  1. Log in to the management console.
  2. Click in the upper left corner and select the desired region and project.
  3. Under Computing, click Elastic Cloud Server.
  4. Click the name of the target ECS.

    The page providing details about the ECS is displayed.

  5. Set Auto Recovery to Enable or Disable.
    Automatic recovery is enabled by default.
    • Once a physical host accommodating ECSs breaks down, the ECSs with automatic recovery enabled automatically migrate to a functional host. This minimizes user service interruption. These ECSs will restart in this process.
    • If Auto Recovery is disabled, you must wait for the system administrator to recover ECSs when hardware becomes faulty.