Ceph cache tiering
Like erasure coding, the cache tiering feature has also been introduced in the Ceph Firefly release, and it has been one of the most talked about features of Ceph Firefly. Cache tiering creates a Ceph pool that will be constructed on top of faster disks, typically SSDs. This cache pool should be placed in front of a regular, replicated, or erasure pool such that all the client I/O operations are handled by the cache pool first; later, the data is flushed to existing data pools.
The clients enjoy high performance out of the cache pool, while their data is written to regular pools transparently.
Generally, a cache tier is constructed ...