High performance media for high performance drives.New SDLT (Super DLT) See DLT. 600 tape drive technology has imposed new capacity and performance demands on media manufacturing processes. As tape technology evolves, new higher-performing magnetic particles and tighter tolerances must be developed to keep pace with industry growth and end user data management needs.
To achieve the required capacity and performance targets, SDLT II media incorporates a broad range of enhancements. The result is a tape cartridge See cartridge. with vastly improved magnetic performance and enhanced durability to handle the demands of Quantum's SDLTtape 600 drive technology.
SDLTtape II media is a dual-coated media that employs a highly precise coating process to achieve a durability requirement of one million head passes. This formulation is based on a new ultra-fine ceramic armor metal particle that is 40% smaller than first-generation SDLTtape media and possesses a higher magnetic power of 2600 oersted Pronounced "erst-ed." The measurement of magnetic energy. The higher the Oe rating in a material, the more current is required to change its magnetic polarity. Named after the Danish scientist, Hans Cristian Oersted (1777-1851), it is used, for example, to measure the coercivity with superior archival properties. The particles, uniform in shape and size, are less than 60 nanometers long. By contrast, the technology used in Super DLTtape I media has a particle size Particle size, also called grain size, refers to the diameter of individual grains of sediment, or the lithified particles in clastic rocks. The term may also be applied to other granular materials. of 100nm. Each metal particle is coated with a thin ceramic layer to protect it from corrosion and oxidation, and provide advanced archival storage durability.
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To maximize the magnetic performance of the particles, new binder and base film components were developed by double-coating a base film layer, wet on wet, with a thick nonmagnetic protective layer and an extremely thin magnetic outer layer. The high-performance binder system combines two different binders mixed with cross-linked material, allowing for a strong connection of metal particle and increased durability.
The recording layer is a mixture of 80% magnetic particle and 20% binder materials. The recording layer coating includes head-cleaning agents and two classes of lubricants lubricants
preparations for the lubrication of passages to reduce frictional injury, e.g. oily preparations, including petroleum jelly, lanolin or water-soluble preparations such as methyl cellulose. to minimize friction between the tape and the read/write heads. The combination of two lubricants meet high-duty cycle demands of SDLT 600 drives by reducing tape and head wear, and repelling airborne debris that can clog the heads and affect read/write performance.
The advanced tape coating technology is supported by a new Super polyethylene terephthalate Ter`eph´tha`late
n. 1. (Chem.) A salt of terephthalic acid. (S-PET) base film, a super-tensilized (pre-stretched) version of the PET base film used in SDLTtape 1 media. S-PET's formulation reduces the overall thickness by 10% and contributes to capacity improvement by enabling an additional 200 feet of tape inside SDLTtape II cartridges. The combination of higher-performance metal particles, an enhanced binding system, the ultra-smooth coating surface, and S-PET base film allows Super DLTtape II media to accept shorter wavelength recording. This achieves higher data density and performance with better signal response and improved signal strength than Super DLTtape I media or other technologies.
SDLT II media relies on an extremely thin, smooth back-coating layer to support one of the SDLT's optical servo An electromechanical device that uses feedback to provide precise starts and stops for such functions as the motors on a tape drive or the moving of an access arm on a disk. positioning system. The common method of creating servo-positioning tracks on the tape is to embed magnetic servo tracks between the data tracks on the recording surface, reducing the physical space available to write data. SDLTtape II's servo design leverages the Pivoting Optical Servo (POS (1) See point of sale and packet over SONET.
(2) "Parent over shoulder." See digispeak.
POS - point of sale ) technology introduced with the first-generation SDLTtape.
Instead of using conventional magnetic servo technology that is the norm with other tape technologies, the back-coat layer of Super DLTtape II media is embedded Inserted into. See embedded system. with microscopic optical servo tracks which are read by a laser to provide highly accurate head positioning. This is a necessity with the extreme density of SDLT 600 drives. Because of this unique design, Super DLTtape II media is not susceptible to high magnetic fields High magnetic fields
Magnetic fields that are large enough to significantly alter the properties of objects that are placed in them. Valuable research is conducted at high magnetic fields. that can impact tape cartridges with magnetic servo positioning tracks. In fact, media that rely on servo tracks that have to be magnetically preformatted at the factory can be rendered inoperable inoperable /in·op·er·a·ble/ (in-op´er-ah-b'l) not susceptible to treatment by surgery.
Unsuitable for a surgical procedure. , and critical data lost forever by such exposures.
The Future: Beyond SDLTtape II
The enhancements represented by Super DLTtape II media provide the technology base to enable the next generation of SDLT technology, expected to provide a native capacity of 600GB and 1.25TB compressed capacity per cartridge. Figure 2 shows the next two stops on the SDLT roadmap, from SDLTII through to SuperDLTS-5. Reaching these capacities with yesterday's magnetic particle technology could prove problematic around the one-terabyte mark, as there are physical limitations to the particles themselves that will inhibit further capacity improvements.
To reach native terabyte-class tape cartridge capacities and beyond, Maxell has developed Neo Super Maximum-capacity Advanced Reliability Tape (NeoSMART)--a collection of advanced technologies and production methodologies designed to support native capacities of up to 10TB per cartridge and beyond. NeoSMART technology is built around a new magnetic particle--NanoComposite Advanced Particles (NanoCAP)--which solves some of the fundamental problems that limit the capacity potential of current acicular acicular /acic·u·lar/ (ah-sik´u-ler) needle-shaped.
needle-shaped. (needle-shaped) magnetic particles.
To date, the push for higher capacities has focused on the development of smaller acicular particles that can be packed more densely on the tape--the approach used with the particles for SDLTtape II media. However, as the needle-like magnetic particles become smaller, both coercivity On magnetic media, the amount of electrical energy required to change the polarization of a bit. The coercivity of hard disks ranges from 500 to 2,000 Oersted. On magneto-optic media, it takes between 5,000 to 10,000 Oersted. See Oersted. (ability to retain magnetic energy) and saturation magnetization (amount of magnetic energy) that are essential for increasing recording capacity and density tend to decrease. This trade-off between coercivity/magnetization and particle size has been the primary impediment A disability or obstruction that prevents an individual from entering into a contract.
Infancy, for example, is an impediment in making certain contracts. Impediments to marriage include such factors as consanguinity between the parties or an earlier marriage that is still valid. to major capacity increases. It is theoretically difficult to continue to engineer needle-like particles for advanced magnetic tapes that require higher recording densities.
NanoCAP technology resolves these issues with a magnetic particle that enables improvements in magnetic energy not simply by downsizing (1) Converting mainframe and mini-based systems to client/server LANs.
(2) To reduce equipment and associated costs by switching to a less-expensive system.
(jargon) downsizing the needle-like magnetic particles, but by the evolution of the individual particle itself. NanoCAP particles are produced through advanced miniaturization min·i·a·tur·ize
tr.v. min·i·a·tur·ized, min·i·a·tur·iz·ing, min·i·a·tur·iz·es
To plan or make on a greatly reduced scale.
min to create ultra-fine spherical-shaped particles with excellent coercivity and saturation magnetization for advanced magnetic recording performance.
NanoCAP particles have a diameter of about 20nm, about one-third the size of SDLT II particles and one-fifth the size of needle-like metal magnetic particles such as those employed in earlier generations of DLT (Digital Linear Tape) A magnetic tape technology originally developed by Digital for its VAX line. The technology was later sold to Quantum, which makes it available to other manufacturers. DLT uses half-inch, single-hub cartridges similar to IBM's 3480/3490/3590 line. , SDLT and LTO (Linear Tape Open) A family of open magnetic tape standards developed by HP, IBM and Quantum (formerly the Certance subsidiary of Seagate) that are licensed to third-party vendors. LTO cartridges contain a memory that stores historical usage data. . This delivers extraordinary magnetic performance, coercivity exceeding 3000 oersted, and extremely high saturation magnetization of over 120emu/g. NanoCAP offers a 200% improvement over Barium-Ferrite magnetic particles, well known for high coercivity and long considered one of the more promising candidates for future high-density magnetic recording media.
The innovative spherical shape of NanoCAP particles allows the closest possible packing structure, enabling higher recording densities and allowing the use of a thinner magnetic layer coating that can boost output levels. NanoCAP particles are also well suited for vertical magnetic recording in future recording methods.
Although the SDLTtape roadmap is not specified beyond 2.4TB (compressed), NanoCAP technology offers a viable method to take SDLTtape beyond the 10TB level.
SDLT II drives and media, and the development of the NanoCAP and NeoSMART technology platforms are just the latest examples that demonstrate that tape is still an evolving and vital storage technology. As data requirements scale into hundreds of terabytes or petabytes, and vast amounts of corporate data must be maintained and archived, the role of tape may change, but the need for tape will not.
Rich D'Ambrise is director of technology for Maxell Corp. of America (Fair Lawn Fair Lawn, borough (1990 pop. 30,548), Bergen co., NE N.J., across the Passaic River from Paterson; inc. 1924. It is residential with light industries. , NJ)