05-01-2021 | | By Robin Mitchell
Recently, IBM and Fujifilm demonstrated their latest tape drive technology that can hold 580TB per tape. What is tape memory, why is it still being used, and what is it used for?
Recently, IBM and Fujifilm announced their latest development in tape memory technology with a single tape cassette storing 580TB of data with a data density of 317 Gbit per square inch. Unlike other memory technologies, tape memory has one of the fastest-growing trends with a yearly increase of 37%, while traditional hard drives have grown by 7.6% per year.
On the memory tapes themselves, each data line is only 56.2nm wide, and the total length of the tape is 1,255 meters long. By comparison, LTO-9 tapes (which are a common industry standard), store 24 TB of raw data, while LTO-12 tapes store 144TB of data. According to IBM, tape drives will help hybrid cloud systems for decades to come due to the inability for hard drives to continue to increase in size quickly enough.
Of course, some engineers may look at this news report and ask themselves why tape memory, the stuff found in the 1960’s computers, is still being used? What advantages could such memory have over modern solid-state systems and other memory solutions?
Tape memory is a memory technology that uses the same principle found in magnetic hard disk drives. Tape memory consists of a polymer strip that is coated in a ferromagnetic material whose changing magnetic polarisation indicates data bits. A read/write head is pressed into the tape, and the tape is pulled across the head and thus the changing magnetic patterns induce a current in the read head. Thus, the orientation of the magnetic polarization itself is not important, but the change in magnetic polarisation.
Magnetic disk storage, or HDDs, use rotating platters which allow read/write heads to quickly seek to any location whereas a tape needs to be rewound and replayed to get to specific locations. Because of this, tape storage is never used as a place for quick data storage of frequently used files.
Magnetic tape was developed in 1928 and its use as a memory medium goes back to the first large computers. Many other memory technologies have been developed since including solid-state FLASH, high-density HDDs, and even ferromagnetic RAM. However, tape memory plays an important role in the back-up industry for a number of reasons.
To start, magnetic tape is one of the cheapest memory storage methods. While tape memory has a life expectancy of 30 years, it provides extremely high memory densities at very low costs and size. The size of an HDD compared to a similar tape drive would see several orders of magnitude more data stored on the tape. Furthermore, tapes can quickly be copied, thus making copies of a tape is relatively straight forward.
Secondly, the sheer size of magnetic tape storage makes it highly ideal for backing up large amounts of data such as that found on servers, mainframes, and data centres. Since the data is unlikely to be accessed, tapes can have entire data centres stored onto them and then committed to storage, only be recalled in the event of a system failure.
Thirdly, tape storage, for its size, is also highly portable and the use of an air gap (i.e. the ability to remove it from a system), provides the ultimate protection against hackers and malware. Once disconnected, no system can interfere with the stored data, thus a compromised data centre can simply wipe all of its drives, restore data from tape, and resume operation.