Magnetic tape is a type of physical storage medium that uses a thin magnetizable coating on a long and narrow strip of plastic film to store digital information. The coating allows data to be stored by magnetizing it in different directions. The history of magnetic tape dates back to the 1930s when it was first developed in Germany for audio recording purposes. By the 1950s, magnetic tape started being used for data storage on early computers. Since then, it has become a widely used medium for backing up and archiving data due to its longevity, low cost, high data density, and portability compared to other storage mediums.
The origins of magnetic recording tape can be traced back to Fritz Pfleumer, a German engineer who registered a patent for a magnetic recording system using tape in 1928. In 1932, BASF created the world’s first commercially available magnetic recording tape under the brand name Magnetophon. The earliest use of magnetic tape for data storage was in 1951 when it was used on the Eckert-Mauchly UNIVAC I, one of the first commercial general purpose computers. In the subsequent decades, innovations like vacuum columns, automatic tape loaders, and built-in error checking improved capacity and performance, making magnetic tape the predominant backup medium for mainframe computer systems.
While other technologies like hard disk drives and solid state drives have become more popular for primary storage, magnetic tape continues to be commonly used for secondary backup and archival data storage across many industries and applications where longevity, portability, and low cost are key requirements.
How Magnetic Tape Works
Magnetic tape stores data through magnetization. It consists of a long strip of plastic film with a thin magnetic coating. As the tape passes by a tape head inside a tape drive, electromagnets in the head can alter the magnetic properties of spots on the tape to represent binary data – a 1 or a 0. The presence or absence of a magnetic spot represents one bit of data. By aligning many magnetic spots in a row, data can be encoded on the tape.
The tape head contains tiny C-shaped electromagnets with gaps between them called read/write heads. To write data, the heads magnetize tiny spots on the tape as it moves by. The presence of a magnetic spot represents a binary 1, while the absence represents a 0. To read the data back, the tape head detects the magnetic or nonmagnetic spots as the tape passes by again. In this way, data can be stored, retrieved and rewritten on magnetic tape.
The density of data storage on magnetic tape has increased dramatically over time, from a few megabits per square inch in early tapes, to multiple terabits per square inch on modern drives. Advanced technologies like perpendicular magnetic recording, shingled writing, and BaFe particles have enabled this improved density.
Advantages of Magnetic Tape
Magnetic tape has several key advantages that have led to its longevity as a storage medium. Some of the main benefits include:
High capacity – Magnetic tape can store large amounts of data in a small physical space. A single tape cartridge can hold up to 15 TB of compressed data, with experimental tapes reaching 220 TB and beyond[1]. This makes tape ideal for back-up and archival applications that require high capacity storage.
Long shelf life – Magnetic tape can retain data for decades if stored properly. Tape cartridges have an estimated shelf life of 30 years or more if kept in proper environmental conditions[2]. This gives magnetic tape an advantage for long-term data retention needs.
Portability – The small physical size of tape cartridges also makes them highly portable. Tape is easy to transport securely offsite for back-ups or to transfer large data sets between locations. This portability and durability benefits many use cases.
Disadvantages of Magnetic Tape
While magnetic tape offers some significant advantages as a storage medium, it also has some notable downsides. Two of the biggest disadvantages of magnetic tape are:
Slow Access Times
One disadvantage of tape is that it has very slow random access times compared to hard drives and solid state drives. Since the data is written sequentially along the length of the tape, reading any particular piece of data involves winding through the tape to find it. This makes accessing individual files or data very slow compared to other storage media like hard drives that allow random access. According to Salvagedata.com, this sequential access means “it can take a long time to back up or restore data stored on tape.”
Fragility
While modern magnetic tape is fairly durable if properly stored, it is still susceptible to damage from mishandling or adverse environmental conditions. As Teach-ICT notes, “each tape does have a limited life span and eventually the quality of the data stored on it will deteriorate.” Things like stretching, warping, dust, moisture and temperature extremes can all contribute to data loss or corruption. Proper handling and storage is essential to preserve tapes. So magnetic tape requires more careful maintenance than other storage media to preserve integrity and avoid data loss over time.
Use Cases
Magnetic tape is commonly used for backups, archives, and storing large datasets due to its high capacity and low cost per gigabyte compared to hard drives and SSDs.
Backups are one of the most common use cases for magnetic tape. Tape drives allow users to perform full backups of systems and store them offline for disaster recovery purposes. This provides an air gap that protects backup data from cyber attacks compared to always-online backup destinations.
Archives are another key use case. The long shelf life (30+ years) and offline nature of magnetic tapes makes them well-suited for long-term archival storage. Content libraries, scientific data, medical records, and more are commonly archived on magnetic tape.
For storing extremely large datasets that reach into the petabyte range, magnetic tape is often the most cost-effective solution. The low cost per terabyte compared to hard drives enables massive storage capacity. This makes tape ideal for data-intensive applications like high-performance computing, geospatial imaging, video archives, and more.
Major technology companies like Google, Amazon, Microsoft, IBM and others rely on magnetic tape for backups, archives and large-scale data storage across their operations. Tape remains an essential medium for managing the explosive growth of big data.
Latest Advances
Magnetic tape technology has continued to evolve in recent years, with manufacturers focusing on increasing storage capacities and developing new form factors. For example, IBM and Fujifilm announced a new magnetic tape in 2021 that can store 580 TB of data, a record capacity for the medium.1 This was achieved by using advanced servo technology to allow over 6000 data tracks across the tape width, as well as optimizing the magnetic layer and employing new head technologies.1
In addition to conventional magnetic tape cartridges, new form factors have emerged such as Sony’s cartridge-free magnetic tape reel that eliminates the plastic casing to improve capacity. This Ultra High Capacity optical tape storage (OCA) system can store up to 330 TB per reel.
These capacity and form factor improvements allow modern magnetic tape solutions to keep pace with the rapid growth of data across many industries. The technology continues to evolve to handle higher densities and new use cases.
Magnetic Tape vs. Hard Drives
Magnetic tape and hard disk drives (HDDs) are two major technologies used for long-term data storage. They have some key differences when it comes to capacity, access times, and durability:
Capacity – Magnetic tapes can have much higher capacities than HDDs. For example, a single LTO-8 tape cartridge can store up to 12 TB uncompressed, while consumer HDDs top out around 16 TB. Data centers use magnetic tapes for archival storage since they pack lots of data into a small physical space.[1]
Access times – HDDs can access data much faster, with average seek times under 10 ms. Magnetic tapes are sequential access media, so it can take minutes to locate a particular piece of data. This makes tapes better for sequential reads/writes.
Durability – Both have comparable shelf lives of around 10-30 years. However, magnetic tapes are more durable for long-term archival storage since HDDs are mechanical devices with moving parts that can fail over time.
Overall, magnetic tapes outperform HDDs when it comes to capacity and long-term archival storage. But HDDs provide much faster random access to data.
Magnetic Tape vs. Cloud Storage
When comparing magnetic tape and cloud storage, there are tradeoffs in security, costs, and accessibility to consider. On security, magnetic tape may have an advantage as the data is physically stored offline rather than on remote servers that could be compromised. However, proper encryption can help secure cloud backups. Tape backups can have lower long term costs compared to cloud storage fees, though the initial investment in a tape library is higher. Accessibility favors the cloud, as backups can be instantly accessed from anywhere rather than requiring physical tapes to be loaded and read locally. According to one source, “With tape, backups are not automatic nor as frequent as is possible with cloud backups.” (https://www.seagate.com/blog/benefits-replacing-tape-backup-with-cloud-storage/)
In summary, while tape offers more security and lower long term costs, cloud backups provide much greater accessibility and automation. Organizations must weigh their priorities like recovery time objectives and budget when choosing between the two backup methods.
The Future of Magnetic Tape
Despite the emergence of newer storage mediums, magnetic tape continues to play an important role as a reliable long-term archival solution for data. Industry experts project magnetic tape will continue being used for the foreseeable future due to its unique benefits.
While hard disk drives currently offer higher capacities for active data storage, magnetic tapes can reliably store data offline for decades. Major corporations and institutions with valuable data require a safe place to archive historical records and protect themselves against loss. As digital content grows exponentially each year, experts predict tape archives will remain an essential part of the data storage hierarchy.
In the future, magnetic tape capacity and density will continue improving through ongoing research and development. For example, Fujifilm recently announced a breakthrough technology for a new Strontium Ferrite magnetic particle that enables over 400 TB native capacity per tape cartridge, allowing for 80x greater capacity than current LTO-9 drives. Innovations like this will enable tape to keep pace with the world’s growing data storage needs.
While cloud and online storage meet most day-to-day needs, magnetic tape provides an offline air-gap that offers unparalleled protection against cyber threats. Organizations handling valuable IP, regulated data, or records requiring long retention will likely continue leveraging magnetic tape storage alongside other modern mediums.
Conclusion
Magnetic tape has been an integral data storage medium since the 1950s, known for its longevity, portability, and cost-effectiveness. While hard drives and cloud storage may be more popular today, magnetic tape continues to play a vital role for long-term data archiving thanks to its unique advantages.
As we covered, the main benefits of magnetic tape include its durability, with a shelf life of 30 years or more; high capacity, with a single tape cartridge able to store up to 15 TB uncompressed; energy efficiency, using very little power; and security, as tapes can be easily removed and stored offline. Tape is the primary backup medium for enterprises and cloud providers due to these strengths.
However, magnetic tape does have downsides like slow sequential access speeds and vulnerability to environmental threats like magnets or physical damage. Tape drives and infrastructure can also be expensive compared to hard drives. As a result, magnetic tape is best suited for secondary storage and archiving, while HDDs and SSDs are preferable for primary and active data.
Recent innovations like LTO-9 show there is still room for growth, with tape capacities and speeds continuing to improve. While the technology faces challenges from other storage mediums, its unique advantages for long-term, offline data retention ensure magnetic tape will continue playing a key role in the future of enterprise data storage.
