Failback replication errors

The following errors can occur during reverse replication (failback data sync) in AWS Elastic Disaster Recovery. Each section describes the error message, its cause, and the resolution steps.

Error: AWS Replication Agent is not connected to DRS

Error message

AWS Replication agent is not connected to DRS. Verify the agent is installed and running, and that it has connectivity to the service

Cause

After you initiate reverse replication, the agent on the recovery instance cannot communicate with the AWS Elastic Disaster Recovery service.

Resolution

To resolve this error, complete the following steps:

1. Verify that the agent is installed and running on the recovery instance. Run the following command for your operating system:

   • Linux:

     systemctl status aws-replication-agent

   • Windows:

     Get-Service AwsReplicationService

2. Verify that the recovery instance has internet connectivity or a NAT gateway connection.

3. If both the agent and connectivity are confirmed working, reinstall the agent as a recovery instance and retry reverse replication.

Error: Credential retrieval failed (clock skew)

Error message

botocore.exceptions.CredentialRetrievalError: Error when retrieving credentials from cert

Cause

The Failback Client uses Amazon Linux 2 and certificate-based authentication. Amazon Linux 2 assumes the hardware clock is set to UTC. If the BIOS or EFI clock is set to local time instead of UTC, authentication fails because of time skew.

Resolution

To resolve this error, complete the following steps:

1. Access the BIOS or EFI Shell of the failback target server.

2. Set the hardware clock to UTC (not local time).

3. Restart the Failback Client.

Note

This error commonly occurs when failing back to physical servers or hypervisors where the hardware clock was configured for local time.

Error: Some recovery instances could not be processed

Error message

Some Recovery instances could not be processed: recovery-instance-id

Cause

This error occurs during reverse replication when both of the following conditions are true:

• The Launch into source instance setting is enabled in the source Region's default launch settings.

• The source Amazon EC2 instance is missing the required tag AWSDRS:AllowLaunchingIntoThisInstance.

Resolution

To resolve this error, use one of the following options:

• Option 1 – Disable the Launch into source instance setting in the source Region's default launch settings.

• Option 2 – Add the tag AWSDRS:AllowLaunchingIntoThisInstance to the source Amazon EC2 instance.

Note

Review the impact before you disable Launch into source instance. This setting affects all future recovery launches for the account in this Region.