Hardware shape

Choose NAS drive bays from the next expansion

Choose the enclosure around the next storage decision, not just the smallest array you can assemble today.

Two bays are a different path

A two-bay mirror is straightforward, but capacity growth eventually requires replacing both drives or replacing the enclosure.

More bays create choices

Four and six bays can support different redundancy layouts and staged growth, but every layout still needs a separate backup target.

Plan the replacement order

Platform rules determine when larger replacement drives add usable capacity. Confirm the exact expansion path before making a partial upgrade.

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

Capacity

Estimate storage growth before choosing drive size

Expansion

Plan drive replacement before buying larger disks

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
NAS enclosure and vdev planning before a first purchase or expansion.
Next check
Carry the bay target into chassis compatibility, platform, acoustics, networking, and regional-availability checks.
Synology drive replacement and expansion guidancePlatform-specific conditions for capacity changes after drive replacement.Open source ↗TrueNAS ZFS Capacity CalculatorZFS capacity, redundancy, and configuration-planning reference.Open source ↗