When Ceph cache tiering is configured as a read-only mode, it works only for the client's read operations. The write operations are not handled in this mode and they are stored in the storage tier. When any client performs read operations, the cache-tiering agent copies the requested data from the storage tier to the cache tier. Based on the policy that you have configured for the cache tier, stale objects are removed from the cache tier. This approach is ideal when multiple clients need to read large amounts of similar data, for example, social media content. Immutable data is a good candidate for the read-only cache tier.