Database startup now includes an EXAStorage metadata overlap check by default

Detail name	Value
Changelog Number	31127
Type	Improvement
Status	Resolved
Fix Versions	Exasol 2026.1.1, Exasol 2025.1.12
Resolution Date	2026-07-02

Background

Previously, the database was able to continue the startup process even if EXAStorage metadata contained overlapping device partitions (inconsistent storage state). This made it difficult to detect problems with the storage metadata before it caused further damage.

Improvement

During database startup, EXAStorage performs a metadata overlap check. By default, startup is blocked if overlapping HDD partitions are detected or if the check cannot be completed reliably. A new startup parameter, -hddOverlapStartupThreshold, controls how strictly the check result is enforced. In less strict modes, startup can continue, but detected inconsistencies or check failures are still logged for diagnosis.

Depending on the result and the configured threshold, the log may contain messages such as:

• "Database startup blocked by HDD overlap check: detected WARNING storage metadata inconsistencies."
• "Database startup blocked by HDD overlap check: detected CRITICAL storage metadata inconsistencies."
• "Database startup blocked: HDD overlap check could not be completed."

Note

If your database does not start because of this check, please contact Exasol Support. If you need to start the database regardless, you can allow database startup by setting the database parameter -hddOverlapStartupThreshold=4, however this is not recommended because the database is then running in an inconsistent state.

Changed behavior