The Design And Implementation Of File System For Hybrid NVM And Block Storage

File system is an important module of operation system.The performance of file system has great impact on computer system and is limited by the speed of storages.NonVolatile Memory(NVM),which can be byte-addressed,accessed in a couple of nanoseconds,is a good candidate of persisted storages.When a system is equipped with NVM and block devices.In order to take advantage of high speed of NVM and the capacity of block devices,it is worth to consider how to manage multiple storage media and store file data in different media.In this paper,a high-performance hybrid file system,called Hybrid Memory File System(HMFS)is designed.It has high bandwidth of accessing files on NVM.The storage capacity of the files system is expanded with block devices.A file in HMFS can be stored across the NVM and block devices.Following studies are done in the paper.1)High-speed access file.data of files are organized with page table.Processes access file data through continuous virtual address.With the Memory Management Unit(MMU),HMFS can efficiently determine the location of data and convert virtual address to physical address.CPU can access data on the NVM smoothly,and data on the block device will be detected by MMU and handled by page fault handler.2)High-performance management of free space.Single list is used to manage the free space of NVM.A new management called resource pool is designed for block devices.3)A swap mechanisms are designed for HMFS to migrate data between NVM and block devices.Keepping the mapping of NVM address to block of block device to reduce I/O operations.4)Optimizations for Non-Uniform Memory Access(NUMA)Architecture.The CPU process running on will be bound with the file.Finally,we designed experiments to test performance of HMFS.The results show that the hybrid file system proposed in this paper can achieve up to 50 G / s read bandwidth and 30 G / s write bandwidth when accessing files on NVM.Data accessed on block devices can be achieved 3G / s read and write bandwidth;When access file whose data is on NVM and block devices,HMFS can have 20 G / s read bandwidth on test condition.