The recent advances in big data analytics and artificial intelligence have led to great advancements and incentives for business processes. Regulatory requirements now require organizations to store records for longer periods than what was done before. Studies show that the amount of data being recorded is showing an upward trend of 30-40% annually. Taking the projections into account the traditional methods of storage, modern hard drives, which were used to store most of the data, is increasing at less than half that rate. Fortunately, the majority of this information doesn’t need to be accessed instantly which makes magnetic tapes the perfect solution for storage of the modern-day data.
Technology hasn’t frozen the power of Magnetic Tape that has been around for a long while and has advanced enormously over the decades.
Magnetic Tape Over the Years
The first commercial digital tape storage system, IBM’s Model 726, had the capacity to store 1.1 megabytes on one reel of tape. With the modern technologies, a modern tape cartridge can store 15 terabytes, and a single robotic tape library has the capacity to store 278 petabytes of data. Storing so much data on compact discs would need 397 million of CDs, which if stacked would be a staggering 476 kilometers high.
There are shortcomings of the tape as well, as it does not offer the fast access speeds of hard disks or semiconductor memories. Keeping the disadvantages aside, the positives are many. Tape storage is more energy efficient, as when all the data has been recorded, a tape cartridge simply sits quietly in a slot over a robotic library consuming minimum or no power. Increasingly, tape is an exceedingly reliable storage medium, with error rates that are four to five orders of magnitude lower than those of hard drives. The tape is very secure medium, with built-in, on-the-fly encryption and additional security provided to the users. If a cartridge is not mounted in a drive, the data cannot be accessed or modified, additionally the “air gap” is particularly attractive over the growing rate of data theft through cyber attacks.
The offline nature of tape provides an additional line of defence against buggy software, for instance in 2011, a flaw in a software update led Google to accidentally delete saved emails in about 40,000 Gmail accounts. The error occurred despite there were data backups stored on hard drives across multiple data centers. Fortunately, the data was additionally recorded on tape, from which Google could eventually restore all the lost data.
The 2011 Gmail incident was one of the first disclosures where a cloud service provider deployed tape for its operational data storage. In the recent times, Microsoft disclosed that its Azure Archive Storage uses IBM tape storage equipment
The Cost Economics
The main reason why companies use tape is cost economics as tape storage costs one-sixth the amount business enterprises have to pay to keep the same amount of data on disks, which makes tape systems a common storage option. The growth of tape will continue to grow for many years at a rate of around 33% annually, which means users can expect to double the capacity roughly every two to three years.
The cost reductions have been due to the exponential increase in the density of information which can be recorded on each square millimeter of the magnetic substrate. As the tapes have a much larger surface area available for recording, modern day tape systems provide a cartridge capacity of up to 15 TB which is more than the highest-capacity hard drives available in the market.
However, tape and hard drives are very different based on their performance characteristics. The long length of the tape that holds the cartridge which is normally hundreds of meters and results in average data access times of 50 to 60 seconds compared with just 5 to 10 milliseconds for hard drives. The rate at which data can be written on the tape is interesting twice the rate of writing to disk.
Since the old times, the areal density scaling of data on hard disks gone down from an average of around 40% a year to between 10 and 15% currently.
The Future Ahead
The future is exciting as there are few technologies under development that could make hard-drive scaling beyond today’s superparamagnetic limits. These advancements include heat-assisted magnetic recording (HAMR) and microwave-assisted magnetic recording (MAMR), techniques which enable smaller grains allowing smaller regions of the disk to be magnetized. The exciting future approaches add to cost and introduce vexing engineering challenges. With the prospective success, however, the benefits to the manufacturers are likely to remain limited.