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Optical media is set to be archival standard

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Since the emergence of flash storage such as USB thumb drives, the use of optical media including CDs and DVDs has seen a steady decline, writes Ruben Naicker, Verbatim product specialist at DCC.
Flash storage is quicker, more portable and convenient for data sharing and transfer, which has led to optical discs being relegated as an out-dated storage media technology. However, storage capacity on optical disks has grown over the years, and now new optical media technology is changing this perspective.
With the introduction of Verbatim’s patented M-Disc technology, optical media is set to become the new standard for long-term data archiving, replacing magnetic media like tapes and offering unprecedented levels of durability, reliability and longevity.
One of the biggest challenges around optical media is its physical nature. A standard DVD, for example, has a polycarbonate layer, a dye layer, an adhesive layer and a reflective layer, onto which the laser of a DVD writer ‘burns’ data. During the write process these layers are vulnerable to corruption and write failure, which means the disk is rendered useless and data stored on it cannot be accessed. The type of dye used in the dye layer can also affect the longevity of data storage.
Standard optical media has a lifespan of around 50 years, while archival quality disks offer up to 100 years of storage. In addition to degradation over time, sunlight can adversely affect standard optical media. The reflective layer is also affected by damage from scratches, dirt and dust, which can make accessing data stored on the disk a challenge as these marks make it difficult for the laser in a CD or DVD player to read the disk.
M-Disc represents an entirely new optical media technology, not simply another improvement to the dye layer. M-Disc features a patented ‘rock-like’ layer between the polycarbonate and adhesive layers, on to which data is engraved, creating physical changes to the layer for permanent data storage. This new standard in digital storage is designed to preserve and protect files as it is resistant to light, temperature, and humidity.
According to Verbatim, “industry standard ISO/IEC 10995 tests carried out by Millenniata showed the expected mean lifetime of an M-Disc DVD to be 1,332 years, with just 5% of disks showing signs of data loss after 667 years.”
The projected lifespan of these discs can therefore safely be in the region of several hundred years at least, and they can be written and read using a standard DVD or Blu-Ray disk device, making them ideal for archival storage.
M-Disc technology is the result of collaboration between Brigham Young University (BYU) in Utah and the US Navy to develop a data storage media that could satisfy two requirements: real archival longevity and the ability to withstand harsh Navy operational conditions. Aside from its impressive lifespan, it is also a non-magnetic media format, which means that unlike a hard disk drive or tape, it is not vulnerable to or affected by electromagnetic conditions. In addition, optical media is a write-once technology, which means that after data is stored there are no moving parts that could result in hardware failure, which could in turn negatively affect data access.
As an alternative to tape, optical media such as M-Disc technology is ideal as it offers complete backward compatibility. Where tape storage typically offers support for two previous generations of media, the latest optical drives can still read the first CDs ever made.
Regardless of media, from a standard DVD or Blu-ray to M-Disc solutions, the same drive is used to read and write. This backward compatibility also ensures a low total cost of ownership, data does not need to be transferred to new media every second generation as it is with tape.
Optical disks can also be stored at ambient temperatures without requiring cooling like hard drive servers do, which dramatically reduces energy costs. In addition, archived data can be accessed quickly in comparison to sequential media such as tape, and optical represents true write-once technology, meaning it cannot be accidentally overwritten or edited after the disc is created.
While the cost of this media is still relatively high in relation to tape, it requires investment into hardware and software, and capacity is at present limited to 100Gb per disk, this is rapidly changing and we can expect capacity of 200Gb and more to be available in the near future. The benefits for data archiving cannot be ignored, as data will remain accessible, uncorrupted and easily available for generations to come. Optical media is thus ideal for protecting data that is too important to lose for legal or operational reasons, and for convenient, reliable data archival.