Among various data backup methods, tape storage remains a cornerstone technology, especially for enterprises looking for long-term data retention.
What is tape storage?
Tape can be considered one of the oldest electronic data storage technologies. The principle of tape is to store and read data by writing and reading magnetic traces on a magnetic recording medium using a magnetic head. Tape storage technology originated in the 1950s and was initially widely used for recording music, video, and other media.
While tape has largely been replaced by SSDs and HDDs as the primary storage medium, it remains the best choice for many businesses for archiving and backup due to its high capacity, low cost, and long durability.
The main challenge of tape storage is the high latency when loading into tape drives, but it offers significant advantages in archiving and backup, where latency is not a critical concern. Many film companies store footage on tape, and industries like oil and gas also use tape to transport data from the field.
Currently, tape is often used in conjunction with object storage to meet the demand for low-latency file access. Of course, sometimes tape is completely replaced by object storage.
Components and Working Principles of Tape Storage
Typically, tape storage consists of tape media, a magnetic head, a tape transport mechanism, and control circuits.
Tape media refers to the magnetic material used to store data information. Tape media usually consists of a magnetic layer, substrate, and surface coating. The magnetic layer is a material that can be magnetized. The industry has now shifted to barium ferrite, as it supports vertical magnetic recording and offers high recording data density. Barium ferrite is used in enterprise tapes from Oracle and IBM, as well as in the LTO Consortium’s Linear Tape-Open Ultrum format tapes. The substrate supports the magnetic layer and is typically made of plastic or metal, while the surface coating protects the magnetic layer.
The magnetic head is a device capable of reading and writing magnetic traces, typically composed of a small electrode and magnetic material, which can be used to erase, write, and read magnetic tracks.
Additionally, the tape transport mechanism controls parameters like the speed and direction of tape transport. It usually consists of a motor and a transmission device with pressure rollers and drive wheels to control tape winding and transport.
Finally, the control circuits manage the operation of the magnetic head and tape transport mechanism, enabling reading, writing, and erasing operations. Control circuits generally consist of a controller, a driver, and an interface for connection with computers or other devices.
The working principle of tape storage is to read and write magnetic tracks using a positioning magnetic head, which is typically placed opposite the tape transport mechanism. As the tape runs, the positioning magnetic head can read or write magnetic tracks within the tape. Data on the tape is stored by writing magnetic traces. When reading data, the magnetic head reads and decodes the magnetic traces, converting them into digital data.
It is important to note that tape libraries are purely mechanical, so they tend to have more failures than X86 servers, which is a critical consideration when using tape libraries.
Advantages and Disadvantages of Tape Storage
First is the cost advantage. Tape has lower expansion costs compared to hard drives. One tape drive can correspond to a large number of tape products; when users need to expand capacity, the tape solution only needs to consider the cost of the storage media, which hard drives cannot match.
Second is the capacity advantage. The latest data tape products are coated with nano-sized magnetic particles, which not only shrink in size but also show more stable physical properties. Simply put, more particles per unit area lead to increased data storage capacity.
Third is the stability of long-term preservation. Tapes typically have a 30-year shelf life. The stability of tape recording has been verified multiple times in extreme environments, and tape storage has been proven to experience faults only after reading or writing 10,000 PB of data, while also providing WORM tape (write once, read many) that prevents data from being overwritten or modified.
Fourth, compared to disk storage, tape is much easier to move. In disaster recovery scenarios, as long as the tape is far enough from the affected data center, its data remains unaffected, allowing enterprises to use it for data recovery.
However, the recovery speed is significantly faster when restoring data from disk. This is because disks can provide random access, making the search for specific data a quick process. Additionally, disk-based backup products typically perform backups continuously, whereas tape backup frequency is lower, such as once daily. Therefore, enterprises generally do not rely on tape storage for recent backups. Moreover, enterprises must ensure that their tape libraries are compatible with their infrastructure.
Notably, with the increase in ransomware attacks, the offline nature of tape storage has become a significant selling point. Network attacks cannot affect storage tapes that are not connected to the network. In this scenario, tape even surpasses cloud backup; although cloud is an increasingly common backup platform, its online nature makes it vulnerable to network threats.
Types of Tape
Based on the working principles of read-write tapes, they can be divided into helical scan technology, linear recording (data stream) technology, DLT technology, and the more advanced LTO technology.
Currently, LTO is the most popular tape format on the market. LTO technology not only increases tape channel density but also allows for comprehensive improvements in magnetic heads and servo structures. LTO technology employs an advanced track servo tracking system to effectively monitor and control the precise positioning of the magnetic head, preventing issues of adjacent track overwriting, thereby achieving higher track density.
Main Application Scenarios of Tape Storage
Cold data: low-cost storage for large data with low access probability;
Backup: log backups, database backups, etc.;
Archiving: archiving historical data and long-term storage;
Innovative uses: for example, as a large-capacity, low-cost recycle bin.
Conclusion
The creation of digital data continues to grow at a rate of 25% or more each year, and at least 80% of global digital data is low-activity data most suitable for secondary storage. In response to this challenge, the tape ecosystem has significantly expanded its capabilities in recent years. From initial backup to later archiving goals, modern tape supports many big data applications that have historically been significant in the expensive HDD space. Tape has also become a primary security solution against cybercrime, offering pure long-term storage solutions through seamless integration of air gap, encryption, and WORM capabilities, ensuring that the stable trend of tape innovation will continue into the future, exhibiting strong vitality.
Vinchin Backup & Recovery will soon support tape backups, providing users with a more flexible backup solution. Stay tuned for this new feature to enhance your data protection and recovery capabilities!
