Review TrueNAS dRAID spare allocation before creating the pool

Bottom line: Review the dRAID allocation before creating the pool. Keep distributed spare capacity and the automatically chosen disk population distinct from the ordinary spare-VDEV workflow.

Source fact: what the authority says

The TrueNAS 25.10 pool-creation guide removes Manual Disk Selection when a dRAID layout is chosen and uses different Automated Disk Selection options. The same choice replaces the wizard’s separate Spare VDEV section with Distributed Hot Spares in the Data VDEV section. Distributed Hot Spares allocates spare disk areas across the VDEV, and its number cannot be changed after pool creation. The Children total and Number of VDEVs choices depend on the other dRAID layout and allocation selections.

What the source does not establish

This article reviews the versioned dRAID creation controls and fixed spare count. It does not qualify a particular topology, guarantee resilver speed or replace a workload-specific redundancy and capacity assessment.

Applicability questions

• Why is dRAID the proposed layout for this pool?
• Which actual disks and automated-selection options are in scope?
• What distributed spare count does the owner intend to accept at creation?
• Who will reconcile the resulting children and VDEV population before creation?

DSE recommendation: controlled next steps

The following steps are DSE recommendations based on the cited source.

DSE recommends reviewing the intended dRAID layout before opening the creation wizard with production disks. Prepare a diagram that separates parity choice, data width, distributed spare allocation, total children and VDEV count. Have another storage operator reconcile the planned device population with the available hardware inventory.

Treat the distributed spare count as a creation-time acceptance item. Ask the owner to record the chosen count and its design rationale in the pool proposal. Do not offer a later count adjustment as an assumed rollback, and keep hardware qualification and the wider recovery design in their separate reviews.

Use a disposable representative system to examine how the automated selections interact. Compare two expressly proposed layouts and record the offered children and VDEV populations without creating a production pool. Resolve a mismatch between the design and available choices before authorizing any destructive disk assignment.

Make the final configuration preview a second-person checkpoint. Match each selected device to the approved inventory and confirm the accepted layout and spare count together. Preserve any existing data through the organization’s separately verified recovery process, and require explicit authorization for the actual pool-creation operation.

Verification and evidence

Proposed verification: record the layout and automated-selection fields in the disposable exercise, then reconcile the displayed pool preview with the intended children, VDEVs and distributed spare allocation. Ask the second operator to identify which count is fixed after creation. Treat an unexplained selection change as a failed design review.

If creation is separately authorized on test disks, compare the resulting reported topology and device identities with the accepted preview. Retain that bounded configuration evidence without asserting a capacity, rebuild-time or workload-performance guarantee. Require the storage owner to accept those separate objectives through an appropriately designed qualification and recovery exercise.

Official references

• TrueNAS — Create Pool — official product documentation; confirm the installed release and configuration.

Source review completed October 30, 2026. Recheck the official documentation and deployment-specific applicability before a production change.