A light-weight log-based hybrid storage system

The Internet of Things (IoT) and cloud computing are two important technologies in our life. They are integrated together to support each other. However, with the rapid development of IoT, the disk-based storage systems in clouds fail to process and analyze data timely from IoT devices. In order to improve the storage capabilities of traditional disk-based storage systems, we present a light-weight log-based hybrid storage system, which comprises of the phase change memory (PCM), flash memory-based SSD and disks. These devices are merged as a single block device with a continuous linear-address space. We also design and implement a log-based hybrid file system called HFS for the block device. By combining the semantic characteristics of data with distinct performance characteristics of devices, HFS optimizes the file system layout and overcomes the shortcomings of traditional log-structured systems. We implement HFS in the Linux kernel and compare it with modern file systems such as Ext4 and F2FS. Evaluation results show the efficiency of the proposed light-weight log-based hybrid storage system.