  NVM is used as a new hierarchy in the storage system, due to its intermediate
speed and capacity between DRAM, and its byte granularity. However, consistency
problems emerge when we attempt to put DRAM, NVM, and disk together as an
efficient whole. In this paper, we discuss the challenging consistency problems
faced by heterogeneous storage systems, and propose our solution to the
problems. The discussion is based on NVPC as a case study, but can be inspiring
and adaptive to all similar heterogeneous storage systems.
