Introduction to Zerto Virtual Replication : Import Methods for AWS : AWS Import
  
AWS Import
This method uses a combination of the AWS import-instance and import-volume APIs for the boot and data volumes respectively. This was the only method supported until version 5.5.
Each machine that you intend to protect must have at least 250MB free space. This is because AWS adds files to the recovered machines during failover, move, test failover, and clone operations.
Protected boot volumes are recovered in EC2 as EBS disks with magnetic disk type. Virtual machines with disks that are less than 1GB are recovered with disks of 1GB. Additional volumes might be created in the recovered instance, dependent on the instance type used for the recovery. These volumes can be ignored.
Protected volumes are recovered in EC2 as EBS disks with magnetic disk type. Virtual machines with disks that are less than 1GB are recovered with disks of 1GB. Additional volumes might be created in the recovered instance, dependent on the instance type used for the recovery. These volumes can be ignored. Temporary disks may be created based on the selected instance size.
The maximum protected data volume and boot disk size is 1TB.
The AWS ImportInstance API only supports single volume VMs. The boot volume of the protected virtual machine should not be attached to any other volume to successfully boot. For more information, see http://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_ImportInstance.html