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PASSEDdatabase / db_backup_restore_failure
Database Backup Restore Failure During DR Test
During a disaster recovery test, the database backup restore fails at 78% completion due to a corrupted backup chain. The backup verification job discovers that 3 incremental backups have invalid checksums, making the entire backup chain since the last full backup unrestorable. Production database has no valid point-in-time recovery option for the last 5 days.
Pattern
DATABASE_EVENT
Severity
CRITICAL
Confidence
95%
Remediation
Remote Hands
Test Results
| Metric | Expected | Actual | Result |
|---|---|---|---|
| Pattern Recognition | DATABASE_EVENT | DATABASE_EVENT | |
| Severity Assessment | CRITICAL | CRITICAL | |
| Incident Correlation | Yes | 22 linked | |
| Cascade Escalation | N/A | No | |
| Remediation | — | Remote Hands — Corax contacts on-site support via call, email, or API |
Scenario Conditions
SQL Server 2022 with full + incremental backup strategy. Full backup: weekly (Sunday). Incrementals: every 4 hours. 3 incremental backups corrupted due to disk controller error. Last valid restore point: 5 days ago. Production database: 2TB. DR test scheduled quarterly.
Injected Error Messages (2)
Database backup restore failed at 78% — RESTORE DATABASE terminated abnormally, backup file 'incr_20260325_1200.bak' checksum verification failed, 3 incremental backups in chain have invalid checksums (corruption detected on backup storage disk controller), last valid full backup: 5 days ago (Sunday), RPO violated: 5 days of data at risk, slow query replay from transaction log also failing due to missing log chain segments
DR database restore incomplete — RESTORE WITH NORECOVERY failed on incremental #47 of 52, database 'production_dr' stuck in RESTORING state, cannot bring online without completing restore chain, backup chain broken since 2026-03-24 12:00, no valid point-in-time recovery available, slow query log analysis confirms data integrity gap, DR test: FAILED
Neural Engine Root Cause Analysis
The primary root cause is hardware failure of the backup storage disk controller, which has corrupted multiple incremental backup files (at least 3 in the chain) as evidenced by checksum verification failures. The database restore is failing at 78% completion because the backup file 'incr_20260325_1200.bak' has invalid checksums due to this storage corruption. This hardware-level corruption has also broken the transaction log chain segments, preventing log replay recovery, leaving the system with only a 5-day-old full backup and violating the Recovery Point Objective.
Remediation Plan
1. Immediately stop the failing restore operation to prevent further corruption. 2. Verify backup storage disk controller status and replace if confirmed faulty. 3. Restore from the last known good full backup (5 days old) to establish a working baseline. 4. Assess data loss impact and coordinate with business stakeholders about the 5-day RPO violation. 5. Implement emergency backup procedures using alternative storage while rebuilding the backup chain. 6. Once hardware is replaced, perform full system backup and establish new incremental backup chain. 7. Review backup validation procedures to detect storage corruption earlier.
Tested: 2026-03-30Monitors: 2 | Incidents: 2Test ID: cmncju92v04qcobqe7ep2x3in