Redis itself already supports a number of persistence schemes and has since the beginning: https://redis.io/topics/persistence
I might be off (and probably am) but if I remember correctly Redis persistence is more for disaster recovery - you can create snapshots and recover them or replay a log file. That's very different in terms of performance guarantees from persisting the data itself to disk and reading from it.
I was under the impression that's what tools (like this one) and stuff like Ardb try to solve.
It's just that Redis is mostly an in-memory database and if the process is terminated and restarted (for all sorts of reasons) the data can be restored from disk.
So what IceFireDB might be good for is data which would not fit easily into the memory of one node.
Again, it's really not clear to me.
It's unclear.