Explanation

AWS Snowball Edge compute-optimized devices is the correct choice because:

• Petabyte-scale data transfer: Snowball Edge devices are specifically designed for transferring large datasets (petabytes) that would be impractical or too slow to transfer over the internet
• Offline transfer strategy: Snowball provides a secure, physical device that you load data onto and ship back to AWS, making it ideal for offline transfers
• Compute-optimized for efficiency: The compute-optimized version includes additional processing capabilities that can help with data processing during the transfer, increasing operational efficiency
• High capacity: Snowball Edge devices can handle up to 80 TB of data per device, making them suitable for petabyte-scale migrations

Why not the other options:

• AWS Snowcone devices: Too small capacity (8 TB) for petabyte-scale data transfer
• AWS Storage Gateway: Designed for hybrid cloud storage integration, not for bulk data migration
• AWS DataSync: Online data transfer service, not suitable for offline strategy and may be too slow for petabyte-scale data

The Snowball Edge compute-optimized devices provide the best combination of high capacity, offline transfer capability, and processing efficiency for this petabyte-scale migration requirement.