The most cost and energy-efficient way of storing data is still tape. Offline data storage is still a major requirement for many organisations. For the fifth time since 2006, IBM has achieved an increase in areal density, with tape developed by Sony. The team from IBM Research team in Zurich, Switzerland and Sony team in Japan collaborated to deliver a 20 fold increase in tape capacity. Both announced these development results during the 28th Magnetic Recording Conference (TMRC 2017) held in Japan.
Tape capacity improvements
IBM announced this in a press release which also provides some history. (IBM sets new record for magnetic tape storage; makes tape competitive for cloud storage). Sony’s press release provides additional detail on manufacturing the tape. (Sony Develops Magnetic Tape Storage Technology with the Industry’s Highest Recording Areal Density of 201 Gb/in2).
IBM produced their first drive 60 years ago, the 726 Magnetic Tape Unit. It used half-inch wide tape with a 2 megabyte capacity. Their demonstration multiplies that capacity 165 million times. It is also a 13 times increase in track density over IBM’s current state of the art TS1155 tape drive.
201Gb/in2 equates to 330TB of native capacity for a tape cartridge. 330TB is a lot of information and compares to 330 million books, which when placed on a bookshelf would stretch just over the length of Japan. A variety of new techniques achieve this high density.
- Advanced signal-processing of the data channel, using predictive noise detection, enabling reliable operation. The processing supports a linear density of 818,000 bits per inch with a 48nm wide tunnelling magneto-resistive (TMR) hard disk drive-style read head.
- A set of servo control technologies that enable tape head positioning with an accuracy of better than 7 nanometers. Combined with the read head this allows a track density of 246,200 tracks per inch, boosting tape capacity.
- A low friction tape head technology that allows the use of smooth tape media.
The tape is also unique. Sony has developed a low-friction coating that allows for reduced friction between the tape and tape head, allowing for increased tape speed and data transfer rates. The lubricant bonds durably to the magnetic layer of the tape. That magnetic layer features nano-grained crystals, with an average grain size of 7 nm. Sony expects this technology to allow for tape cartridges holding more than 1000 meters of tape.
“Tape has traditionally been used for video archives, back-up files, replicas for disaster recovery and retention of information on premise, but the industry is also expanding to off-premise applications in the cloud. While sputtered tape is expected to cost a little more to manufacture than current commercial tape that uses Barium ferrite (BaFe), the potential for very high capacity will make the cost per TB very attractive, making this technology practical for cold storage in the cloud.” – Evangelos Eleftheriou, IBM Fellow