Review TrueNAS configuration continuity before switching boot environments

Bottom line: Plan the configuration and audit comparison before switching boot environments. Retain the required environment deliberately and keep the OS selection separate from wider data-recovery acceptance.

Source fact: what the authority says

The TrueNAS 25.10 Boot reference describes an upgrade creating a separate boot environment that inherits the core configuration; other state is not transferred into it. It cautions that repeated moves between environments can leave their configurations different and distribute the audit history across them. Keep protects a chosen environment from the updater’s space-reclamation deletion when a new environment lacks sufficient room. Deletion is unavailable for the default boot environment and for the environment currently activated.

What the source does not establish

This article covers the documented boot-environment state and retention boundaries. It does not establish compatibility of a later configuration with an earlier OS, or certify a boot environment as a backup of application data.

Applicability questions

• Which environment is running, which is proposed, and why is the switch needed?
• What configuration and audit evidence must remain understandable across the change?
• Which environment needs deliberate retention during the review?
• What separate service and data checks must follow a successful boot?

DSE recommendation: controlled next steps

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

DSE recommends a transition note identifying the running and proposed environments and the configuration changes since the proposed target. Have the administrator and service owners agree which changes must remain, be reapplied through a supported method or be intentionally abandoned. Do not infer that requirement from an environment name alone.

Preserve the available configuration and relevant audit evidence before switching. Keep environment identifiers with each artifact so later reviewers can understand which state produced it. Plan where an investigation will obtain records from both sides rather than merging unlabeled logs and assuming a continuous history.

Review the needed retention choice before a subsequent update or cleanup operation. Identify the environment to keep and record why it is still required. Leave deletion outside the initial recovery action; make that decision only after the approved environment and service checks have been accepted.

Use a representative nonproduction arrangement for the first recovery rehearsal. Include a harmless documented configuration change between the two selected states as a proposed test input. Ask its owner to state the intended result before switching, with a separately reviewed path back if the result differs.

Verification and evidence

Proposed verification: record the environment selected and the environment actually running after the authorized reboot. Compare the agreed configuration items with their written dispositions. Inspect the available audit records with their environment identities, keeping any gap or split visible in the evidence record.

Perform the named service checks after the boot result is known, and test any separate application-data recovery requirement through its approved plan. Retain the actual observations without substituting a successful login for full acceptance. Stop cleanup while a configuration difference or required audit segment remains unexplained.

Official references

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

Source review completed October 29, 2026. Recheck the official documentation and deployment-specific applicability before a production change.