Analysis of SSD with Logical to Physical Address Mapping of Hot Data to Single Level Cell Area

Flash Friendly File System (F2FS) proposed by Sam-sung Electronics manages data by dividing it into hot/warm/cold for maximizing the advantages of flash memory and efficient data management. In this system, hot data is more timing critical than cold data, and the Program-Erase cycle (P/E cycle) may be more important because hot data is frequently read and written data. In flash memory cells, Single Level Cell (SLC) is faster and has higher endurance than Multi Level Cell (MLC), Triple Level Cell (TLC), and Quad Level Cell (QLC). Conventional SSD uses the SLC caching technique using the fast speed of SLC, and we approached this aspect to configure an environment to program and read hot data into the SLC area of the flash memory cell. For this experiment, the environment was implemented using a storage emulator called FEMU, and the SSD received data temperature information from the (F2FS) and had to modify the Flash Translation Layer (FTL) based on this information. We experimented with workloads of fileserver and webserver in a benchmark tool called filebench, and it was confirmed that programming/reading hot data into the SLC area improves overall performance.