What are Data Tapes? - Magnetic tape storage devices explained
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Brief introduction to the mechanism behind data tape technology. Meanwhile, connect with ODSI - Online Digital Solutions, UK by following the below mentioned links: ODSI Blog: www.odsi.co.uk/blog Twitter: http://bit.ly/1ai6Zwe Facebook: http://on.fb.me/1ai6Ys7 LinkedIn: http://linkd.in/18C2WE6 Google+: http://bit.ly/15s113Z Pinterest: http://bit.ly/14ia10O While connect with me at the following: LinkedIn: http://linkd.in/17yrzog Email: zoey.zurnab@odsi.co.uk
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What are Data Tapes? - Magnetic tape storage devices explained
- 2. What are Data Tapes?
- 3. “Data storage device that reads and writes data on a magnetic tape” • Magnetic Tape – Long and narrow strip of plastic film – Magnetized undercoating of strip – Various levels of magnetized data are stored on strip • Magnetic Tape Data Storage – Digital recording on magnetic tape to store digital information – Commonly enclosed in cartridges and cassettes – Tape Drive performs writing or reading of data
- 5. • Digital Recording – Digital audio and video are directly recorded on a storage device – Direct encoding of data into the stream of discrete numbers which represents: • Changes in air pressure for audio and chroma & luminance values for video through time • Recording Process – Recording – Playback • Techniques to Record to Commercial Media – Digital Cassettes • Read/write head moves quickly in order to maintain a high enough speed to keep the bits at a manageable size – Optical Disc Recording • A laser is used to burn microscopic holes into the dye layer of the medium • A weaker laser is used to read these signals • Digital Information – Discrete, discontinuous representations of information or works
- 6. History of Data Tapes
- 7. • Open Reels – Wound on large (10.5 in/26.67 cm) reels – Standard for large computers • Univac – First commercial data tape UNIVAC I - 1951. – Used in UNISERVO – Drive’s recording medium: • A thin metal strip of 0.5 inch wide – Nickel-plated phosphor bronze • Recording density was 128 characters per inch – Linear speed of 100 in/s • Eight tracks: – Six data tracks – One parity track – One timing track
- 8. • IBM Formats – Used ferrous-oxide coated tape – Magnetic tape dimensions were 0.5 inch – Wound on removable reels up to 10.5 inches in diameter – Different tape lengths were available • 1200 ft., 2400 ft. • Introduction of half inch tapes – Tape lengths increased in 1980’s • Started using PET film – Early half-inch tape had 7 parallel tracks of data along the length – 9 track tapes supported the new 8-bit characters – Effective recording density increased over time • Common 7-track densities started at 200, then 556, and finally 800 cpi • 9-track tapes had densities of 800, 1600, and 6250 cpi • End of file was designated by a tape mark • End of tape by two tape marks
- 9. • DEC Tape I – 0.75in wide tape, having: • 6 data tracks • 2 mark tracks • 2 clock tracks – Data recorded at roughly 350 bits per inch – Durable to be used as the main storage medium for a OS – First time used file sharing system – Shoe shining – 1970’s – Slow disk drive • DEC Tape II – DEC tape II was introduced around 1978 – Same structure but used a much smaller 0.150 in tape – Enclosed in a cartridge – The TU58 DEC tape II drive had an RS232 serial interface • Allowed it to be used with the ordinary serial ports – Low cost floppy disk technology • DEC tape II got obsolete
- 10. • Cartridges and Cassettes – Cassette • An enclosure that holds two reels • Single span of magnetic tape – Cartridge • A single reel of tape in a plastic enclosure
- 12. • Tape Width – Half inch • Recording Method – Linear • Linear Serpentine – Scanning • Transverse • Accurate • Helical Linear Recording Linear Serpentine Recording
- 13. • Data Blocks – Data is written on tape in blocks – Important to keep up with data rate • Data Buffer • Modern tapes offer speed matching feature • Sequential Access to Data – Tape provides sequential access to data • Takes 10s to reposition the tape head – Hard disk performs the action in 10s of milliseconds • Offers random access to data
- 14. • Access Time – Tape • Long latency for random accesses – Alternatives available • Indexing • Marking blocks with a tape mark • Data Compression – A ratio of 2:1 is typical – Some enterprise tape drives can encrypt data
- 15. Companies Venturing in Data Tapes
- 16. • 3M • DEC • Sony • HP • Quantum • Storage Tek • Maxell • IBM • Etc
- 17. Tape Products Available at ODSI
- 18. • 8 MM Tape • AIT Tape • Barcode Labels • Cleaning Cartridges • DDS Tape • DLT Tape • DTF Tape • Enterprise Tape • LTO Tape • T10000 Tape • Traven Tape • Tape Storage Cases • VXA Tape • Optical Cartridges • QIC Tape • RDX Cartridges • SDLT Tapes • SLR-MLR Tapes
- 19. 8MM Tapes
- 20. • Magnetic data storage • Pioneered by Exabyte • D8 – Abbreviation used by SONY • Dual reels in cartridge • First Commercial Helical Scan recording • Backward compatibility • 170m length can store up to 170 GB • Enhance length of 225m length stores 250 GB • Tape Mediums: – Metal Particles Tape – Advanced Metal Evaporated Tape (AME) – AME with Smart Clean
- 21. Advanced Intelligent Tape (AIT)
- 22. • Developed by SONY • Dual reels in cartridge • Provides backward and forward compatibility • Uses helical scanning • S-AIT is a variant – Wider tape in larger cartridge – Single reel • 25GB to 1040GB • Technical Features: – AME (Advanced metal evaporated) – MIC (Memory in chip) – R-MIC (Remote memory in cassette) – WORM (Write once read many)
- 23. Barcode Labels
- 24. • Barcodes has adhesive backing • Use for effective management of data tapes • Alphanumeric coding
- 27. Digital Data Storage Tapes (DDS)
- 28. • Store digital data on DAT Tape • Tape width is 3.8mm • Latest formats are 8mm wide • Helical scan recording method • Length can be increased • 2GB to 160GB • DAT Tape: – Developed by SONY – Sequential transmission of data – Ability to record digital data at: • Higher lower and equal sampling rate
- 29. Digital Linear Tapes (DLT)
- 30. • Magnetic tape data storage technology • Owned by Quantum Corp. • Linear serpentine recording • Half-inch wide tape • Tape material is metal particle tape (MP/AMP) • Cartridges contain a single reel • Reel motors controls tape speed and tension – No capstan • DLT includes WORM capability • 2:1 data compression • SDLT is a variant
- 31. Digital Tape Format (DTF)
- 32. • Magnetic tape data storage format • Developed by Sony • Uses a 1/2in wide tape • Cassette with two reels • Helical scan process • Two sizes of tape cassettes; "S" and "L” • Highest capacity DTF 1 media tape is 42 GB • DTF 2 tape delivers storage capacity of 200 GB
- 33. Enterprise Tapes
- 34. • Half-inch tape technology • Few are able to encrypt data • Leading brands – Sun – Imation – Fuji – IBM
- 35. Linear Tape Open (LTO)
- 36. • Magnetic tape data storage – Open standards – Part of quantum corp. – Developed as a replacement for DLT – Standard form-factor goes by the name Ultrium • LTO version 6 holds 2.5tb – 1⁄2-inch wide tape in a single reel cartridge. • Ultrium drive reads data: – From a cartridge in its own generation – From cartridges of at least the two prior generations. • An Ultrium drive writes data: – To a cartridge in its own generation – To a cartridge from the immediate prior generation
- 38. • Capable of writing and rewriting data • Available in 130 mm and 90 mm forms • The disc consists of a ferromagnetic material – Sealed beneath a plastic coating – Reliable and inexpensive medium – Designed in rewritable and WORM formats • Leading companies offering magneto optical cartridges: – Sony, verbatim, IBM, HP, Sony, Philips, Imation, Maxell
- 39. Quarter Inch Cartridge (QIC)
- 40. • Magnetic tape data storage format • Enclosed in a package of aluminum and plastic – Holds two tape reels driven by a single belt • The tape was originally 1⁄4-inch wide • Length is 300 to 1,500 feet – Motorized capstan • Data is written linearly along the length • Could also be written in "serpentine”
- 41. RDX Cartridges
- 42. • Features a removable hard disk cartridge – A docking station for operating the cartridge • The highest capacity is 1 TB • Shock-proof 2.5-inch Serial ATA hard disk drives
- 43. SLR-MLR Tape
- 44. • Perfect backup for: – Mid-sized servers – Small data centers – Workstations • Named by Tandberg Data for its line of QIC • The earliest SLR drive has a capacity of 250 MB • Latest drive has a capacity of 70 GB
- 45. T10000 Tape
- 46. • Latest Oracle/Sun Storage Tek tape drive • Used with large computer system • Tape cartridges are 1⁄2 in (13 mm) wide • Storage Capacity: – T10000A has a native capacity of 500 GB – T10000B drive support 1 TB – T10000C tape drive stores 5 TB natively
- 47. Travan Tape
- 48. • 8 mm magnetic tape cartridge • Developed by the 3M company • 750 inch length • Linear track recording technology • Travan does not verify data after writing • The tape is not attached to the hubs – Wrapped and held by friction
- 51. VAX Tape
- 52. • “Packet technology” data format • Helical scan technology • 2 read heads for Each stripe – Each stripe starts with a unique packet ID – Ends with an ECC packet checksum • Ensures data integrity
- 53. Thank You Website: www.odsi.co.uk Contact: +44 (0) 203 005 9500 Email: Sales@odsi.co.uk Source: Wikipedia
Notas del editor
- ProcessRecordingThe analog signal is transmitted from the input device to an analog-to-digital converter (ADC).The ADC converts this signal by repeatedly measuring the momentary level of the analog (audio) wave and then assigning a binary number with a given quantity of bits (word length) to each measuring point.The frequency at which the ADC measures the level of the analog wave is called the sample rate or sampling rate.A digital audio sample with a given word length represents the audio level at one moment.The longer the word length the more exact is the representation of the original audio wave levelwise.The higher the sampling rate the higher the upper cutoff frequency of the digitized audio signal.The ADC outputs a sequence of samples that make up a continuous stream of 0s and 1s.These numbers are stored onto recording media such as magnetic tape, hard drive, optical drive or solid state memory.PlaybackThe sequence of numbers is transmitted from storage into a digital-to-analog converter (DAC), which converts the numbers back to an analog signal by sticking together the level information stored in each digital sample, thus rebuilding the original analog wave form.This signal is amplified and transmitted to the loudspeakers or video screen.Recording of bitsEven after getting the signal converted to bits, it is still difficult to record; the hardest part is finding a scheme that can record the bits fast enough to keep up with the signal. For example, to record two channels of audio at 44.1 kHz sample rate with a 16 bit word size, the recording software has to handle 1,411,200 bits per second.
- UNIVAC - the actual transfer rate was around 7,200 characters per seconds*Eckert-Mauchly UNIVAC ILinear SpeedTotal distance traveled (in direction of motion) divided by time
- *7 Parallel tracks of the tape allowing, six-bit characters plus one bit of parity written across the tape. This was
- DEC TapeThe fundamental durability and reliability of DECtape was underscored when the design of the tape reel mounting hubs was changed in the early 1970s. The original machined metal hub with a retaining spring was replaced by a lower cost single-piece plastic hub with 6 flexible arms in a "starfish" or "flower" shape.The system would be configured to put temporary swap files on a second DECtape drive, so as to not slow down access to the main drive holding the system programsSerial Communicationthe process of sending data one bit at a time, sequentially, over a communication channel or computer bus. This is in contrast to parallel communication, where several bits are sent as a whole, on a link with several parallel channels
- *While tape can provide a very high data transfer rate for streaming long contiguous sequences of data.**A tape drive usually has to cope with a difference between the rate at which data goes on and off the tape and the rate at which data is supplied or demanded by its host.
- *Apt Transfer rate of data - the deck must wind an average of one-third the tape length to move from one arbitrary data block to another. Indexingwhere a separate lookup table (tape directory) is maintained which gives the physical tape location for a given data block
- Generations:EXB 8200EXB 8205EXB 8305 XLEXB 8500EXB 8505EXB 8505 XLEXB 8700Elian 820MammothMammoth LTMammoth-2These drives use Metal Particle (MP) tape.EXB-82001987 -- EXB-8200 Full-Height form factor246 kB/s data transfer rateEXB-8200SX model features high-speed search1990 -- EXB-8500 Full-Height form factor500 kB/s data transfer rateEXB-8500c model features hardware data compression1992 -- EXB-8505 Half-Height form factor1994 -- EXB-8505XL Half-Height form factor500 kB/s data transfer rate1995 -- EXB-8700 Tabletop (top-loading) form factor8700 model included generic backup software8700LT model included no software8700SW included Cheyenne backup software1998 -- Eliant 820 Half-Height form factorMammothThese drives use Advanced Metal Evaporated (AME) tape, but could also read (but not write) MP tapes.1996 -- EXB-8900 Mammoth 3 MB/s data transfer rateLCD on drive displayed drive status1999 -- Mammoth-LT No LCDMammoth-2 (M2)These drives used Advanced Metal Evaporated (AME) tape with an 2 m integrated cleaning tape header called Smart Clean.1999 -- Mammoth-2 12 MB/s data transfer rate4.6 cm/s tape speed during normal read/write operations1.6 m/s tape speed during search and rewind operations17 s load time, from insertion to readyALDC hardware data compression, 1 kB compression buffer
- Technical featuresAMEAdvance Metal Evaporated is a different formulation of tape media.MICMemory in Cassette Memory chip in the cartridge that keeps relevant information about the tape.R-MICRemote - Memory in Cassette Like MIC except it doesn't require physical contact.WORMWrite Once Read Many functionality, useful for archive keeping.* Maximum data recording capacity of AIT 5 media tape is 1040 GB or 1.04 terabytesGenerations:http://en.wikipedia.org/wiki/Advanced_Intelligent_Tape
- Ensure smooth running of data tapesResults in superior performance
- Digital Audio Tape (DAT or R-DAT) is a signal recording and playback medium developed by Sony and introduced in 1987.[1] In appearance it is similar to a Compact Cassette, using 4 mm magnetic tape enclosed in a protective shell, but is roughly half the size at 73 mm × 54 mm × 10.5 mm. As the name suggests, the recording is digital rather than analog. DAT has the ability to record at higher, equal or lower sampling rates than a CD (48, 44.1 or 32 kHzsampling rate respectively) at 16 bitsquantization. If a digital source is copied then the DAT will produce an exact clone, unlike other digital media such as Digital Compact Cassette or non-Hi-MDMiniDisc, both of which use a lossy data reduction system.Like most formats of videocassette, a DAT cassette may only be recorded and played in one direction, unlike an analog compact audio cassette.Although intended as a replacement for audio cassettes, the format was never widely adopted by consumers because of issues of expense and concerns from the music industry about unauthorized digital quality copies. The format saw moderate success in professional markets and as a computer storage medium. As Sony has ceased production of new recorders, it will become more difficult to play archived recordings in this format unless they are copied to other formats or hard drives.
- http://en.wikipedia.org/wiki/Digital_Linear_Tape
- http://en.wikipedia.org/wiki/Digital_Tape_Format
- 3480 tape family was the first version of Enterprise tape format. Data recording capacity of 3480 media tape cartridge is 200MB. The capacity of the next generation 3490 tape was increased to 400MB. 3490E is the advanced version of 3490 Enterprise tape. 800 MB is the capacity offering of 3490E backup tape. Later on, the 35-series of Enterprise media tape was introduced. Its first tape version was 3570, which offers 20GB recording capacity. 3596 Enterprise tape series are ideal for TS1120 tape dive. 3596 Enterprise cartridge can retain higher data volume of 700 GB. The popular version of Enterprise tape media cartridges are 9940, 9840, 3592, 3590, 3570, 3490 and 3480
- An open standard is a standard that is publicly available and has various rights to use associated with it, and may also have various properties of how it was designed (e.g. open process). There is no single definition and interpretations vahttp://en.wikipedia.org/wiki/Linear_Tape-Openry with usage.
- In physics the magneto-optic Kerr effect (MOKE) or the surface magneto-optic Kerr effect (SMOKE) is one of the magneto-optic effects. It describes the changes to light reflected from a magnetized surface. It is used in materials science research in devices such as the Kerr microscope, to investigate the magnetization structure of materials.Curie point, is the temperature where a material's permanent magnetism changes to induced magnetism, or vice versa. The force of magnetism is determined by magnetic moments.An electromagnet is a type of magnet in which the magnetic field is produced by the flow of electric currenthttp://en.wikipedia.org/wiki/Magneto-optical_drive
- http://en.wikipedia.org/wiki/Quarter-inch_cartridge
- Serial ATA (SATA) is a computer bus interface that connects host bus adapters to mass storage devices such as hard disk drives and optical drives. Serial ATA[2] replaces the older AT Attachment standard (ATA later referred to as Parallel ATA or PATA), offering several advantages over the older interface: reduced cable size and cost (seven conductors instead of 40), native hot swapping, faster data transfer through higher signalling rates, and more efficient transfer through an (optional) I/O queuing protocol.http://en.wikipedia.org/wiki/RDX_Technology
- Most (but not all) modern tape cartridges are 1⁄2 in (13 mm) format tape, first popularized by the IBM 3480 and DEC DLT formats. This is a small, rectangular and easily handled tape cartridge compared to the previously common 7-track and 9-track round tape reels. This form factor has proven to be work well with stand alone drives and for use in automated tape libraries.
- http://en.wikipedia.org/wiki/Travan
- After having done with the storage of data on data tapes. It is important to protect them by putting into the tape storage cases.
- The novel part of VXA packet technology is that each stripe starts with a unique packet ID and ends with an ECC packet checksum. As each stripe is written to tape, it is immediately read back to verify that the write was successful.If the write was not 100% successful the packet can be rewritten at another point on the tape without stopping. When the data is read back, the packets are reassembled into a "buffer" by their packet ID. The buffer has 3 additional ECCs to ensure data integrity.Another aspect of VXA is that there are 2 read heads for each stripe, slightly offset in relation to each other to allow for more flexibility in reading tapes written by other drives.Due to the relatively slow tape speed inherent to helical scan technology, the drive is able to stop and start the tape much more quickly to avoid the need to back hitch.*Packet Technology:In IT (information technology) a packet is formatted unit of data carried by a packet mode computer network. Other networks, that don't support packets, such as point-to-point telecommunications links, simply transmit data as a series of bytes, characters or bits alone.When data is formed into packets, the bitrate of the communication medium can better be shared among users than if the network were circuit switched.When any file (e-mail message, html file, image, graphic or anything) is sent from one place to another via the internet, the TCP (Transmission Control Protocol) divides the files into chunks to an efficient size for transferring. When all these packets arrived they are then reasssembled into the original file.