Capacity

Estimate storage growth before choosing drive size

The first useful number is the protected capacity target for the planning horizon—not the sum of drive labels in a cart.

Start with data classes

Separate irreplaceable photos and documents from replaceable media, caches, downloads, and operating-system images. They need different recovery targets and may grow at different rates.

Use a visible horizon

Choose a one-, three-, or five-year horizon and record the monthly growth assumption. A range is more useful than a false precise forecast.

Leave operational headroom

Snapshots, metadata, temporary copies, and maintenance all consume room. Keep the reserve visible instead of filling a pool to its headline capacity.

Continue planning

Turn this storage question into a capacity baseline.

Use the planner to make growth, bays, redundancy, and recovery capacity visible together.

Build a storage plan

Hardware shape

Choose NAS drive bays from the next expansion

Recovery

Use RAID for availability, not as the only backup

Editorial record

Maintained by Make Your Own Tools to turn “Store data safely” into a defined capacity, bays, redundancy, and recovery baseline. The references below provide the technical context for this planning path. Its calculation rules and planning assumptions are documented in the methodology, and affected calculations pass regression checks before the review date advances.

Last reviewed
Evidence set
2 primary references
Calculation coverage
2 affected rules checked
Read methodology →View change history ↗
Planning scope
Early capacity planning for equal-size drive arrays and appliance NAS storage.
Next check
Carry the target into filesystem-overhead, mixed-drive-layout, and platform-expansion checks.
TrueNAS ZFS Capacity CalculatorZFS capacity, redundancy, and configuration-planning reference.Open source ↗Synology RAID CalculatorCapacity estimation for supported Synology drive combinations.Open source ↗