Design And Implementation Of File Management System For Blu-ray Optical Disc Library

With the advent of Big Data, the scale of data storage is increasing and the energy consumption for data storage is more and more serious. The number of data center in China has more than 400 thousand by 2015, but in most of them, PUE is still greater than 2.2 and the energy efficiency is low. More than 40% of energy has consumed in data storage, so high energy consumption in data storage restrict the development of data center seriously. For high energy consumption in data storage, this paper has presented the Blu-ray disc with low energy consumption as storage medium, and do some research on file management for Blu-ray optical disc library.This paper sets from the data access rules, so data can be classified into hot data accessed frequency, warm data accessed occasionally and cold data that is not accessed but contains a certain amount of value. Because the cold data in storage is as high as 80%, this paper focuses on energy-saving storage for cold data. In order to realize the file managerment and storage in optical disc storage system, the file storage and file classification for Blu-ray optical disc storage system are studied in this paper.First of all, because of the huge difference between the disk and the BD in data transmission rates, this paper designs and implements the file storage of optical disc library to solve the data transmission problem. This mainly includes:(1) function of network sharing, which is used to solve the file transfer and sharing between disk and optical disc library. (2) function of automatic burning, which is used to solve file storage from disk to optical disc library. In big data environment, because the burning capacity of the files is often more than a disc, files are well classified before burning. In addition, since the file will be deleted after stored in the disc, the function of file check is implemented to ensure the integrity of the burning data. (3) file management system, which is proposed to use the userspace file system to manage files in optical disc library. When the disc is off-line, the userspace file system will query file nodes and find the disc ID, and then retrieve disc through socket communication and finally complete access to the off-line disc.Then, this paper designs and implements the data classification based on the file hot-state, which includes file status update, file migration and file classification etc. For the storage files, the data classification will establish a hot-state for each file and classify the files according the hot-state. In the end, the storage system of optical disc library can store the hot data, warm data and cold data respectively to the SSD, HDD and optical disc library.Finally, this paper carries out a number of tests on the automatic burning, file management system for optical disc library and data classification, and analyses the results. The results prove that data storage and data classification for optical disc library in this paper are consistent with the expected results, and meet the design requirements.Today, energy is in short supply. Research on cold data storage and the development of the large-capacity intelligent Blu-ray disc library are not only beneficial to reduce PUE of the data center, but also play a positive role in construction of the green data centers. Classification storage, burning disc program and file system for optical disc library will make a major contribution to implement the project of the large-capacity intelligent Blu-ray optical disc library of lab.