Drive specification

CMR or SMR for a NAS?

Use an exact model check and workload requirements instead of assuming that every drive in a product family behaves the same way.

Best fit

CMR drive

Parity, rebuild, scrub, and sustained-write scenarios where conventional recording is required by the plan or platform guidance.

  • • Check exact model, warranty, workload rating, and compatibility.
  • • Do not use a family label as proof of the specification.

Best fit

SMR drive

Only workloads and platforms whose documented behavior supports the exact drive and write pattern.

  • • Requires more deliberate validation for array workloads.
  • • Marketplace titles are not enough evidence.

Decision rule

Treat this as a model-number verification task. Check manufacturer documentation and platform guidance before adding any drive to an existing pool.

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
1 primary reference
Planning scope
Model-level recording-technology checks.
Next check
Every manufacturer or drive model without an official source.