Applies to: All editions
Verification purpose
Verification provides evidence that expected final data is present at checked logical locations. It is separate from the write operation and must be interpreted according to the selected profile.
Distributed representative verification
The NIST Clear and IEEE Clear profiles select representative sectors distributed across the logical address space, including boundary locations. This is designed to avoid relying on a single beginning, middle, or end sample. Small devices can receive complete verification when their addressable size fits within the verification scope.
A sampled verification result supports the checked logical range. It is not a physical inspection of controller-managed hidden or retired storage.
Fixed and random final patterns
Profiles ending with a known fixed pattern can support sampled comparison with that pattern. Profiles ending in generated random data cannot be rechecked against the exact final stream when that stream has not been retained.
The report therefore distinguishes:
- Write completion;
- Fixed-pattern verification performed and passed;
- Verification performed and failed;
- Verification not applicable or not available for the final pattern.
Media errors and failed ranges
During modern Clear overwrite processing, DriveErase can isolate write failures and continue best-effort processing of other addressable regions where safe. This preserves useful evidence but prevents a complete certified result.
Examples of adverse evidence include:
- Failed write ranges;
- Unreadable or inaccessible locations;
- Flush failures;
- Verification mismatches;
- Changed capacity or identity;
- Interruption before all required passes completed.
Status meanings
- OK: the method completed successfully according to its recorded criteria.
- Completed – Not Certified: the write completed, but one or more certification requirements were not established.
- Incomplete: only part of the required pass sequence or range completed.
- Error: the method could not complete its required operation.
The precise reason appears in the detailed log and report.
Response to an incomplete result
- Do not release or reuse the device based on an incomplete result.
- Preserve the report and detailed error.
- Confirm the controller path, power, device condition, and capacity.
- Run an appropriate health assessment where safe.
- Repeat the approved method only when the device remains reliable enough to process.
- Apply physical destruction when required coverage cannot be established.