Abstract: Performance is very important for the cloud application．There are some differences between cloud and current application in management strategy and access pattern,which leads to the traditional cache management strategy can’t adapt to the requirement of the cloud application．According to the features of cloud application,the cache strategy based on impact factors was designed to implement the storage cache sub-system for cloud application．Metadata and data cache were used to manage separately,making a distinction about the impact of the creation,opening,reading,writing and modifying on the probability of the cache accessed again．Then the two cache correlation strategics were designed to improve the performance of cache management according to the relation between metadata and data．The actively sche-duling strategy was used to improve the adaptability based on eliminating the low impact factor cache entries actively and adjusting the space of metadata cache and data cache dynamically．At last,the prototype was released and was evaluated by Filenench and Postmark．The result shows the storage cache sub-system can improve 1%~120% I/O performance and 2%～87% operation processing speed.

Key words: Cache,Cloud application,File system