DNVMCFS: The Direct Hybrid NVM File System for the Application

The Non-Volatile Memory (NVM) device has higher read and write speed compared with disks and SSDs, and it is the hotspot to improve the efficiency of computer system. But it also makes the I/O software stack become the bottleneck of application's efficiency instead of storage devices. We analyse I/O software stack when the application accesses the NVM device and design a direct hybrid NVM file system which can bypass the VFS to reduce the extra time overhead of accessing the NVM device for the application. The application oriented direct file system interface is design to allow the application directly access the NVM device which reducing the response time and improving the I/O performance of applications. On this basis, we implement the prototype of DNVMCFS and use Fio to test its performance comparing with PMFS, NVMCFS and Ext4 on PMBD respectively. The results show that DNVMCFS can improve the I/O performance by 42.3% compared with PMFS, 50% compared with NVMCFS and 53.7% compared with Ext4 on PMBD. Meanwhile, DNVMCFS can also increase the IOPS where Filebench is used to simulate the real application test. The results show that DNMVCFS raises the I/O performance and IOPS by 25%. These results verify that DNVMCFS provides higher I/O performance and better adaptability.