Portable copy allocation

Field Backup Drive Planner

Turn daily camera ingest into discrete drives for two or three independent field copies, with reserve and unassigned spares included.

Decision guide

Assign each field copy to physical devices

What this tool helps you decide

This planner converts daily primary ingest and the interval before a studio handoff into a count of portable drives. It calculates one complete copy first, then assigns the same discrete capacity to two or three independent copy roles. The output separates assigned devices from unassigned spares and reports expected fill. Its purpose is a travel packing and labeling brief; it does not replace the longer-term archive, backup, or retention design used after the production returns.

Before you start

Use a realistic high-day ingest from the card planner, a prior production, or camera tests. Count days until data reaches storage that you have deliberately accepted as the next protected stage, not simply the scheduled final shooting day. Choose the portable copy count required while traveling. Record advertised drive capacity, formatted free space, and a reserve. A spare drive should remain unassigned so it can replace either copy role without mixing their contents.

How the calculation works

Trip payload equals daily ingest multiplied by shoot days. Safe capacity per drive starts with decimal terabytes converted to gigabytes, then applies the usable formatted percentage and the desired unused reserve. The planner divides one copy's payload by safe drive capacity and always rounds upward. Drives per copy are multiplied by independent copy count, after which unassigned spares are added. Protected writes describe bytes stored across the declared copies, not unique source data.

How to interpret the results

Drives per copy defines two matching sets: for example, A1 and A2 must collectively hold one complete copy while B1 and B2 hold another. Do not treat A1 plus B1 as one set merely because their combined capacity is sufficient. Average fill below 100% reflects the selected usable percentage and reserve. Approximate days per drive is a planning cue for changeover; switch only after the current batch has completed its required copy and verification state.

Worked example

A five-day production creating 420 GB each day generates 2.1 TB of primary material. A 2 TB portable drive at 93% usable capacity with a 15% reserve provides about 1.58 TB of safe allocation. Each complete copy therefore needs two drives. Two independent copies require four assigned drives, and one unassigned spare makes a five-drive kit. The assigned devices average roughly 66% of their conservative capacity at wrap.

Assumptions and limitations

The calculation assumes the daily figure already includes all cameras and audio that belong in the field media batch. It does not model device cost, shock resistance, encryption, power loss behavior, sustained speed, endurance, cable loss, theft, water, customs, or a manufacturer's environmental limits. Multiple drives in one bag share a location risk. RAID inside one enclosure is not automatically an independent second field copy. Capacity availability also says nothing about checksum success.

Next steps

Label every assigned drive with its copy letter, sequence, project, and custody owner. Put different copy roles in separate bags after both verify. Estimate when each batch completes with the Media Offload Time Planner, and close the handoff with the Field Media Copy and Verification Checklist. For post-production working space, archive horizon, and durable backup capacity, continue to the Creator Media Storage Planner.