I'm not familiar with HDF5 but agree on resiliency. We are a collegiate racing team and our car's power rails aren't stable and redundant at all times, so power loss failure is something I've kept in mind from day one on my telemetry project. SQLite is generally equipped to handle power losses and write thread crashes:

> An SQLite database is highly resistant to corruption. If an application crash, or an operating-system crash, or even a power failure occurs in the middle of a transaction...

Quite often after a run the entire car is turned off and, on next power up, the databases are left as .db and .db-journal files. The code has no problem processing or even continuing on logging with DBs in this state.