Problem
By “durable” I mean, the server can crash at any time, and as long as the disk remains in tact, no data is lost (see ACID).
Redis is not usually deployed as a “durable” datastore (in the sense of the “D” in ACID.), even with journaling. Most use cases intentionally sacrifice a little durability in return for speed.
However, the “append only file” storage mode can optionally be configured to operate in a durable manner, at the cost of performance. It will have to pay for an fsync() on every modification.