If everything operates correctly, it should be okay to use unstable writes with commits, even in a cluster, assuming the cluster has proper Grace handling.
So what you mentioned before about using only stable writes to avoid corruption - did you mean this only in the sense of persistency? But IMHO the user should anyways be aware of using `fsync` to make sure data gets to the disk. I was mainly concerned about the interoperability of unstable writes and floating IPs failovers - but you're saying that most FSALs do allow unstable writes to some kind of RAM only cache (e.g. pagecache or some userspace lib) on the ganesha host, and syncing them to the actual disks only on `commit`, and that works with floating IPs, and the client knows to correctly mark pagecache on its side as not dirty anymore only after a commit - right?