An Active File Mode Transition Mechanism Based on Directory Activation Ratio in File Synchronization Service

In this paper, we propose an active file mode change mechanism in which the file synchronization system of cloud storage automatically changes files in a directory of a client to the online or local mode by considering tradeoff between local storage usage and file access time according to directory activation ratio. When the directory activation ratio rises above a certain threshold, the proposed active file mode change mechanism selects online mode files in this directory based on file access delay time and local storage usage and changes them to the local mode to reduce file access delay of active IoT clients. When the directory activation ratio falls below the threshold, the active file mode change mechanism selects the local mode files based on the last access time and local storage usage and changes them to the online mode to increase available local storage. Experimental results show that the proposed active file mode change mechanism can control when and how much the client can reduce and increase the local storage usage and the file access delay by changing file mode parameters according to the requirements of various IoT devices.