Patent attributes
A method for improving asynchronous data replication between a primary storage system and a secondary storage system maintains a cache in the primary storage system. The cache includes a higher performance portion and a lower performance portion. The method monitors, in the cache, unmirrored data elements needing to be mirrored, but that have not yet been mirrored, from the primary storage system to the secondary storage system. The method maintains a regular LRU list designating an order in which data elements are demoted from the cache. The method determines whether a data element at an LRU end of the regular LRU list is an unmirrored data element. In the event the data element at the LRU end is an unmirrored data element, the method moves the data element from the higher performance portion to the lower performance portion. A corresponding system and computer program product are also disclosed.
