SQLite databases
.db members (state.db, kanban.db, response_store.db, …) are not published with a rename like ordinary files. Renaming would replace the file's inode while a gateway, dashboard, or WebUI process still holds the old one open: that process would keep reading pre-import pages and keep writing sessions nobody else can see, and those sessions would simply be absent from the database everyone opens next — with nothing logged. Instead the imported pages are written into the existing database file, the same way /snapshot restore does it, so every open connection converges on the imported data.
If the live database cannot be replaced safely — the page copy failed and another process still holds the file open — the import leaves that database untouched and lists it under Warnings (N files skipped). Stop the holding processes and re-run.
Importing an older backup over newer work is still allowed, but it is no longer silent. When the imported state.db holds fewer messages than the one it replaced, the summary reports it:
From the official Hermes Agent CLI reference.