Thanks Maxim, Guzman.

I think storing responses directly in disk makes it easy to store and retrieve from different process contexts. However, if the storage space is huge (in TB) and if the disk storage media is SSD, write avoidance is something that should be considered. In this case, small files can be stored in memory cache to speed up access to frequent webcontent and cachemanager can try to store big blocks to disks when evicting content from memory cache. Having memory cache and disk cache separated will make more sense in such a case. I was trying to figure out if Nginx supported that concept.