Explanation

Option C is the most cost-effective solution for the following reasons:

1. Data Volume: 5 PB (5,000 TB) is an enormous amount of data. Transferring this over a 1 Gbps internet connection would take approximately:

   • 5 PB = 5,000 TB = 5,000,000 GB
   • 1 Gbps = ~125 MB/s (megabytes per second) = ~0.125 GB/s
   • Time = 5,000,000 GB / 0.125 GB/s = 40,000,000 seconds ≈ 463 days

   This exceeds the 6-month timeline and would incur significant network transfer costs.

2. AWS Snowball with Tape Gateway:

   • Snowball is designed for petabyte-scale data transfer when network bandwidth is insufficient
   • Tape Gateway allows physical tapes to be copied to virtual tapes on the Snowball device
   • Shipping physical devices is much faster and more cost-effective for this volume
   • S3 Glacier Deep Archive is the most cost-effective storage class for data that needs to be preserved for 10+ years with infrequent retrieval

3. Why other options are less optimal:

   • Option A: DataSync over 1 Gbps would take too long (463+ days) and incur high network transfer costs
   • Option B: Direct writing to Glacier Deep Archive over internet would also take too long and may not be supported by all backup applications
   • Option D: Tape Gateway over internet would face the same bandwidth limitations and take too long

4. Cost considerations:

   • Snowball service costs are fixed per device
   • Glacier Deep Archive has the lowest storage costs ($0.00099 per GB-month)
   • No egress costs for compliance data that won't be retrieved
   • Shipping costs are minimal compared to network transfer costs for 5 PB

Key AWS Services:

• AWS Snowball: Physical data transfer device for large-scale data migration
• AWS Storage Gateway - Tape Gateway: Virtual tape library interface
• Amazon S3 Glacier Deep Archive: Lowest-cost storage for long-term archival (10+ years)
• Lifecycle policies: Automate transition to appropriate storage classes