1. An article of manufacture including code to communicate with a storage and a cache in a computer readable memory and cause operations, the operations comprising: adding data units from the storage to the cache, wherein requested data from the storage is returned from the cache; processing a degree of prefetch indicating a number of data units to prefetch into the cache; processing a trigger distance indicating a prefetched trigger data unit in the cache; prefetching the number of data units indicated by the degree of prefetch in response to processing the trigger data unit; and adjusting the degree of prefetch and the trigger distance based on a rate at which data units are accessed from the cache.