In the era of cloud computing and solid state drives, it may seem antiquated to still rely on magnetic tape for data storage. However, tape continues to have an important role in long-term archiving for businesses and organizations. Tape offers benefits like longevity, security, energy efficiency and low cost per gigabyte stored. Major technology companies like IBM, Oracle and Quantum still actively develop tape storage products and technologies. So while tape may seem outdated, it offers unique advantages that make it still relevant for some data storage needs today.
What is magnetic tape data storage?
Magnetic tape data storage uses reels of plastic film coated with iron oxide particles to store digital data. The coating allows bits to be represented as magnetic charges on tape and read back by a tape drive. Tape debuted in 1951 with UNIVAC computers and gained popularity in the 1970s-80s before hard disk drives overtook it.
Tape remains highly sequential, with very slow random access. The linear format means tapes must be physically wound to reach a particular data point. Bit densities have grown enormously, from 200 bpi initially to 148 Gb per square inch today. Current LTO-9 tapes hold 18 TB raw capacity per cartridge. Tape is designed for sequential writing or reading of large blocks of contiguous data.
What are the main advantages of tape storage?
Low cost per terabyte
Tape offers unmatched storage density at very low cost, with LTO-9 media costing around $100 per 18 TB cartridge. HDDs cost around 10x more per terabyte stored. Tape holds this cost advantage due to its simple material composition and ease of manufacturing in bulk.
When not actively being accessed, tapes sit passively requiring no electricity. Tape cartridges consume no energy when sitting idle on a shelf. This offers a huge efficiency advantage compared to spinning hard drives.
Long shelf life
If stored properly under moderate humidity and temperature, tape can retain data for 30 years or more. HDDs and SSDs lose data over time as charge dissipates. Tape’s stability has allowed it to become the go-to choice for long-term archival storage.
Tape media is far more rugged than other storage technologies. Tape cartridges are designed to withstand drops, impacts, vibration, dust, moisture and magnetic fields that would cripple HDDs. This durability makes tape well-suited for backups, archives and transportation of data.
While HDD densities have plateaued around 1-2 Tb per square inch, tape densities and capacities continue to grow exponentially. Each new LTO generation roughly doubles capacity. LTO roadmaps project up to 363 TB raw capacity by LTO-13. No other medium offers such continually scaling capacities.
Storing data offline on tape improves security and mitigates risks of hacking, malware or accidental deletion. Tapes can be easily ejected, transported and stored in a secure location. This “air gap” removes archived data from being modified or corrupted. With HDDs, data is always online and vulnerable.
What are the main disadvantages of tape storage?
Slow data access and transfer speeds
The linear format of tape makes locating and accessing specific data very slow compared to random-access media like HDDs and SSDs. Tapes must mechanically wind to reach requested data, with average seek times around one minute. Transfer speeds peak around 300 MB/s, versus 500+ MB/s for HDDs. This makes tape unsuitable for applications requiring quick data access.
Bulk and manageability
Storing large tape libraries requires dedicated floor space and equipment for storage, retrieval and backups. Manual intervention is needed to load and remove cartridges. Large tape catalogs must be carefully indexed and managed to track contents. This overhead is a hindrance for general purpose computing compared to self-contained HDDs.
Finite read/write cycles
Tape media wears out over time, with LTO-9 rated for a minimum of 80 full write passes. HDDs can be overwritten virtually indefinitely. Rewriting data repeatedly on tape causes gradual degradation compared to more durable SSDs and HDDs designed for repeated operations.
Potential for degradation
While durable overall, tape data integrity can decay over decades if not stored properly. Environmental factors like heat, humidity, magnetic fields and physical damage can cause data loss. Maintaining pristine long-term storage conditions is critical. HDDs better tolerate more variable storage environments.
Costly drives and readers
While media is inexpensive, tape drives and readers are expensive capital investments. LTO-9 drives cost over $4,500. This fixed cost makes it more economical at larger scales. HDDs have become a commodity component integrated into most computers by default.
Is tape storage still used today?
Despite the rise of newer technologies, tape remains a pivotal part of the storage hierarchy for modern data centers. Tape carves out an irreplaceable role in affordable long-term data archiving.
With capacities up to hundreds of terabytes, tape is ideal for taking full system backups that would be too big for HDDs. The portability also enables offsite storage of backup data. AWS Glacier and other cloud archives use tape as part of their data backup infrastructure.
Regulations and business records often mandate data retention for 10-30 years. Tape’s shelf life and low TCO for infrequently accessed data make it the first choice for long-term archival storage. Facebook and other companies use tape for old social media content and closed account data.
Big data and high-performance computing
Supercomputers like those operated by the NSF rely on tape capacity and bandwidth to store the enormous datasets created by scientific modeling and sensors. The Square Kilometer Array radio telescope will generate over an Exabyte of data per day that only tape can practically store.
Media and entertainment
The movie and music industries rely on tape for archiving content masters and unused footage. For example, the original Star Wars film reels were retrieved from tape archives for preservation.Tape offers affordable storage for the 100+ TB master files used in 4K video editing.
Genome sequencers generate terabytes of sequencing data per run that must be preserved. Tape provides reliable long-term storage for these huge datasets well into the future as sequencing costs continue to decline.
Key tape technology vendors
For over 60 years IBM has been a tape technology pioneer starting with their 726 tape system introduced with the IBM 701. They developed the standard 9-track tape format used through the 1970s. Today they offer the TS1160 enterprise tape drive with native data rate of 400 MB/s and 35 TB capacity using barium ferrite tape.
Oracle designs StorageTek-branded tape systems including the SL150 modular library system featuring automatic tape loading and user-replaceable drives. It offers LTO-9 support and up to 370 TB compressed capacity per module. The T10000 T2 drives store up to 10 TB per cartridge.
Quantum produces tape automation equipment and LTO, enterprise and hyper-scale drives. Their most advanced is the Scalar EXA24 400 TB tape library supporting LTO-9 media. Quantum tape systems emphasize long-term data integrity checking and management software integration.
Spectra designs specialized tape libraries optimized for high-capacity deep storage in HPC, research and media applications. Their TFinity Exascale Library can scale up to 2 EB compressed in a slim 19-inch rack format, natively supporting LTO, IBM TS1155 and Oracle T10000 T2 media.
Fujifilm recording media division produces data cartridges for enterprise tape systems. Their barium ferrite (BaFe) metal particle tape aims to maximize capacity, speed and longevity. They claim BaFe media will store up to 123 TB per cartridge in the future.
The future of tape storage
Tape storage has reinvented itself over the decades to offer compelling capacities and economics as a deep archiving solution. While tape has ceded primary storage long ago to HDDs and flash memory, its advantages are enduring for specific long-term cold data storage needs.
Ongoing R&D aims to push tape to even higher capacities through technologies like BaFe media, bit-patterned recording and advanced signal processing. New hardware enhances security with features like LTO cartridge-level encryption. LTO roadmaps project at least 7 more LTO generations through LTO-13 reaching nearly 1,000 TB uncompressed per tape. This ongoing development shows tape storage remaining viable well into the foreseeable future.
While primarily suited for controlled data center environments today, tape technology continues to advance in pursuit of long-term storage cost and density goals that no other medium can yet achieve. Tape occupies a crucial niche that will be needed as long as data continues exponentiating. Any data that must endure and remain safely accessible for decades to come will likely find its way to tape as the most reliable and affordable archival form of storage for the 21st century.
Tape storage retain key roles for long-term data archiving while ceding primary data storage to HDDs, SSDs and flash memory. Advantages like low cost, energy efficiency, high capacities and shelf life continue to make tape the ideal solution for certain backup, archive and HPC applications despite downsides like slow access speeds. Major corporations continue to rely on tape for cost-effective archiving with technology roadmaps projecting denser tape generations well into the future. While tape is no longer used for general computing, it provides unmatched economics for less frequently accessed data in need of safe and affordable long-term retention.