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docs/features/checked/scanner/rpm-legacy-bdb-packages-database-fallback.md

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+# RPM Legacy BDB Packages Database Fallback
+
+## Module
+Scanner
+
+## Status
+VERIFIED
+
+## Description
+Adds fallback support for legacy Berkeley DB (BDB) format RPM package databases alongside the modern SQLite format, enabling package discovery on older RHEL/CentOS images.
+
+## Implementation Details
+- **Berkeley DB Reader**:
+  - `src/Scanner/__Libraries/StellaOps.Scanner.Analyzers.OS.Rpm/Internal/BerkeleyDbReader.cs` - `BerkeleyDbReader` parses legacy BDB format RPM package databases for older RHEL/CentOS images
+- **RPM Database Reader**:
+  - `src/Scanner/__Libraries/StellaOps.Scanner.Analyzers.OS.Rpm/RpmDatabaseReader.cs` - `RpmDatabaseReader` with fallback logic: tries modern SQLite format first, falls back to BDB format for legacy images
+
+## E2E Test Plan
+- [ ] Scan an older RHEL/CentOS image (pre-RHEL 8) using BDB format RPM database and verify packages are discovered
+- [ ] Scan a modern RHEL/CentOS image using SQLite format RPM database and verify it uses the primary path
+- [ ] Verify the fallback logic correctly detects the database format and chooses the appropriate reader
+- [ ] Verify BDB-parsed packages include correct name, version, release, and architecture metadata
+- [ ] Verify both BDB and SQLite paths produce consistent package lists for the same set of installed packages
+
+---
+
+## Verification
+
+| Check | Result |
+|-------|--------|
+| Tier 0 - Source files exist | PASS |
+| Tier 1 - Build + code review | PASS |
+| Tier 2 - Integration tests | PASS |
+| Verified | 2026-02-13T18:10:00Z |