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+# Backup and Restore
+
+## MSSQL Backup Restore
+
+The migration service restores SQL Server backups through the shared backup directory.
+
+Host:
+
+```text
+DATABASE_BACKUP_DIR=/srv/mssql-backup
+```
+
+Migration service:
+
+```text
+/upload/database
+```
+
+SQL Server:
+
+```text
+/var/opt/mssql/backup
+```
+
+Restore scripts should use the shared path so SQL Server can access the uploaded `.bak` file.
+
+---
+
+## Firebird Backup Restore
+
+Firebird support includes original helper scripts from the macOS installer payload:
+
+```text
+/opt/romexis-firebird-db/tools/Romexis_Firebird_Backup.sh
+/opt/romexis-firebird-db/tools/Romexis_Firebird_Restore.sh
+```
+
+Long-term restore strategy should support:
+
+```text
+.fbk backup restore through gbak
+.fdb file handling for compatible database files
+```
+
+For migrations, `gbak`-based restore is preferable because it can bridge Firebird ODS/version differences more safely than copying raw `.fdb` files.
+
+---
+
+## Restart After Restore
+
+The migration service should not directly manipulate the Romexis process from the outside.
+
+Instead, it uses the shared restart state file:
+
+```text
+/data/romexis_images/.romexis_restart_state
+```
+
+Expected pattern:
+
+1. migration service writes restart request
+2. Romexis container notices request
+3. Romexis process is restarted
+4. Romexis container writes result
+5. migration service reads result
+6. migration service removes state file
+
+---
+
+## Final Migration Completion
+
+A completed migration should:
+
+- preserve logs
+- remove temporary SFTP user
+- hide action buttons
+- retain migration state for audit/debugging