Advancing Archival Data Storage: The Promises and Challenges of DNA Storage System

As the volume of data is rapidly produced every day, there is a need for the storage media to keep up with the growth rate of digital data created. Despite emerging storage solutions that have been proposed such as Solid State Drive with quad-level cells or penta-level cells, Shingled Magnetic Recording, Linear Tape-Open, and so on, these technologies still fall short of meeting the demand for preserving huge amounts of available data. Moreover, current storage solutions have a limited lifespan, often lasting just a few years. To ensure long-term preservation, data must be continuously migrated to new storage drives. Therefore, there is a need for alternative storage technologies that not only offer high storage capacity but also long persistency. In contrast to existing storage devices, Synthetic Deoxyribonucleic Acid (DNA) storage emerges as a promising candidate for archival data storage, offering both high-density storage capacity and the potential for long-term data preservation. In this article, we will introduce DNA storage, discuss the capabilities of DNA storage based on the current biotechnologies, discuss possible improvements in DNA storage, and explore further improvements with future technologies. Currently, the limitations of DNA storage are due to its weaknesses including high error rates, long access latency, and so on. In this article, we will focus on possible DNA storage research issues based on its relevant bio and computer technologies. Also, we will provide potential solutions and forward-looking predictions about the development and the future of DNA storage. We will discuss DNA storage from the following five perspectives: (1) We will describe the basic background of DNA storage including the basic technologies of read/write DNA storage, data access processes such as Polymerase Chain Reaction-based random access, encoding schemes from digital data to DNA, and required DNA storage format. (2) We will describe the issues of DNA storage based on the current technologies including bio-constraints during the encoding process such as avoiding long homopolymers and containing certain GC contents, different types of errors in synthesis and sequencing processes, low practical capacity with the current technologies, slow read and write performance, and low encoding density for random accesses. (3) Based on the previously mentioned issues, we will summarize the current solutions for each issue, and also give and discuss the potential solutions based on the future technologies. (4) From a system perspective, we will discuss how the DNA storage system will look if the DNA storage becomes commercialized and is widely equipped in archive systems. Some questions will be discussed, including: (i) How do we efficiently index data in DNA storage? (ii) What is a good storage hierarchical storage system with DNA storage? (iii) What will DNA storage be like with the development of technology? (5) Finally, we will provide a comparison with other competitive technologies.