The Renaissance Of SLR Technology.The fitting replacement for DAT (1) (Dynamic Address Translator) A hardware circuit that converts a virtual memory address into a real address. See also DAT file. (2) (Digital Audio Tape) A magnetic tape technology used for backing up data. technology Magnetic tape has successfully addressed IT market requirements for data backup by providing a secure, high storage capacity, removable media In computer storage, removable media refers to storage media which can be removed from its reader device, conferring portability on the data it carries. A removable drive is a reader device for such media. , at a low cost per MB/GB of recorded storage. Although the demise/displacement of tape has been predicted for years by various CD/DVD/competing removable technologies, tape remains king for serious backup of business data. This article will focus on tape technology applicable to the SMB market See SMB. . This segment consists of IT users who demand reliable low cost backup with a street price of $1500 or less. The unit volume leader in the segment, DAT technology, has reached a pinnacle with the DDS-4 format. The storage capacity demands for the SMB (1) (Small to Medium-sized Business) Also called "SME" (small to medium-sized enterprise), it refers to companies that are larger than the small office/home office (SOHO), but not huge. user are continuing to grow. But DAT technology is now so highly leveraged that DDS-5 products may never materialize. Further enhancements to DAT storage capacity and to a lesser extent transfer rate require either "new inventions New Invention may refer to:
The truncated truncated adjective Shortened capacity of the current DDS (1) (Digital Data Storage) See DAT. (2) (Data Dictionary System) See QuickBuild and OpenDDS. (3) (Dataphone Digital S road map leaves room for other tape technologies to absorb DAT customers whose capacity requirements have outgrown the current DDS roadmap and capture "new" customers in the SMB sector. There are currently at least eight available technology families vying vy·ing v. Present participle of vie. vying vie for market share in the SMB segment. The popularity of DAT has set some consumer expectations for price point, performance, form factor, and availability of family extensions such as automation. In order for a different tape technology to successfully capture the DDS market space it must meet all consumer expectations in these areas as well as effectively address recent computer trends such as "RAS (1) See network access server. (2) (Remote Access Service) A Windows NT/2000 Server feature that allows remote users access to the network from their Windows laptops or desktops via modem. See RRAS and network access server. " (Reliability, Availability, and Serviceability (system) serviceability - The ease with which corrective maintenance or preventative maintenance can be performed on a system (e.g. by a hardware service technician). Higher serviceability improves availability and reduces service cost. Serviceability is one component of RAS. ). The customer will be looking for Looking for In the context of general equities, this describing a buy interest in which a dealer is asked to offer stock, often involving a capital commitment. Antithesis of in touch with. a technology with plenty of headroom head·room n. 1. Space above one's head, as in a motor vehicle, above a doorway, or in a tunnel; clearance. 2. Electronics Dynamic headroom. ; with per drive disk capacities in the 73GB range the customer will look especially close at capacity/performance futures. The customer will require a tape technology that can be cost effectively deployed today and which promises a cost-effective future. A Little Tape History In 1990 the disk industry was on an exponential growth Extremely fast growth. On a chart, the line curves up rather than being straight. Contrast with linear. path (and still is) in terms of capacity and performance; however tape technology was struggling to keep pace. QIC (Quarter Inch Cartridge) A magnetic tape technology introduced in the early 1980s that has been widely used for backup. It was the first popular tape format for PCs. committee companies were no longer able to bring competitive devices to market easily. Each company had different expertise mixes related to recording. Some companies were good at high track density, some at high bit (linear) density, some specialized in multiple data channels. Depending on how a new format was composed particular companies may have been granted competitive advantages based on their expertise. In this environment it was difficult to agree upon development standards lest one company enter the market before the competition. In the early 90s companies were forced to evaluate basic recording techniques and make choices. These choices were based on which format would best suit future requirements for extensions to capacity and performance balanced with "in house engineering expertise". Consideration was given to track density, track pitch, available media area, recording format (helical scan A tape recording method that uses a spinning read/write head and diagonal tracks. Although it uses a rather complex transport mechanism, it is very gentle on the tape. After the cassette is inserted into the drive, the tape is pulled out and wrapped around the read/write head. vs. linear/longitudinal tracks), tape speed, and system dynamics System dynamics is an approach to understanding the behaviour of complex systems over time. It deals with internal feedback loops and time delays that affect the behaviour of the entire system. . Some companies elected to take devices from the consumer sector (8mm Video and DAT audio), which already had relatively high recording density due to high stripe stripe - data striping pitch (track density) and adapt them for data storage usage. These companies created formats specialized for data recording, added enhancements for ECC (1) (Error-Correcting Code) A type of memory that corrects errors on the fly. See ECC memory. (2) (Elliptic Curve Cryptography) A public key cryptography method that provides fast decryption and digital signature processing. , and computer interfaces (SCSI SCSI in full Small Computer System Interface Once common standard for connecting peripheral devices (disks, modems, printers, etc.) to small and medium-sized computers. SCSI has given way to faster standards, such as Firewire and USB. ) to the devices. Still others adopted existing media styles and created new basic formats. 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. (then in the DEC world) has its heritage from the mainframe "3480 square tape". Tandberg Data Tandberg Data (OSE: TAD) is a company focused on data storage products, especially streamers, headquartered in Oslo, Norway. They are the only company still selling drives that use the QIC format (also known as SLR), but also produce VXA, LTO and DLT products, along with elected to stay with the QIC data cartridge (1) A cartridge used to hold computer data. See cartridge. (2) (Data Cartridge) A 5.25" QIC-style magnetic tape technology that originally used the DC-6000 model designation. Tandberg Data (www.tandberg. style. Exabyte (then a start up) was the only company who chose 8mm video as a base technology; many manufacturers developed drives based around DAT drive technology. DAT companies included Aiwa, Archive (Conner/Seagate), Hewlett Packard, RByte, Sony, and WangDAT. Thus diversification in the computer backup tape See tape backup. industry was born in earnest. As we enter the 21st century the tape technology choice war is still going on. The last three years have seen introductions for new helical helical /hel·i·cal/ (hel´i-k'l) spiral (1). hel·i·cal adj. 1. Of or having the shape of a helix; spiral. 2. Having a shape approximating that of a helix. devices (AIT, VXA-1) as well as linear (Onstream, 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. family) drives. It Starts With The Technology Core Technology: A major portion of the basic tape unit cost and performance capability relates to the recording technique chosen. Regarding mechanism cost, all tape drives require a SCSI interface SCSI interface - SCSI adaptor , Data Buffer In computing, a buffer is a region of memory used to temporarily hold data while it is being moved from one place to another. Typically, the data is stored in a buffer as it is retrieved from an input device (such as a keyboard) or just before it is sent to an output device (such , Hardware Data Compression data compression Process of reducing the amount of data needed for storage or transmission of a given piece of information (text, graphics, video, sound, etc.), typically by use of encoding techniques. , and Micro-controller system. It is safe to say cost levels for these components between the various technologies are similar. Where the cost differences between the technologies come in to play is in the components used directly for the recording process such as the magnetic head(s), Electric motor(s) required, actuators required, and precision mechanical components to implement the recording format. In these areas the technologies vary widely. Helical Scan Products: (track is recorded diagonally in "stripes" across face of longitudinal tape) All current helical scan products utilize a dual hub driven cassette/cartridge and a rotating multi-channel recording head. A separate motor is required to control each tape hub as well as one for spinning the recording head (3 electric motors). In addition, the tape guidance path on all helical drives is contained fully inside the drive (requiring precision mechanical components/guides) adding complexity/cost. Generally two other actuator A mechanism that causes a device to be turned on or off, adjusted or moved. The motor and mechanism that moves the head assembly on a disk drive or an arm of a robot is called an actuator. See access arm. motors are required for cartridge housing, load/unload, and tape threading/wrap around the head. As far as capacity futures are concerned DAT, 8mm, AIT, and VXA-1 helical scan products have less available total tape area then TRAVAN, SC50, SLR (1) (Scalable Linear Recording) A line of magnetic tape drives from Tandberg Data that evolved from the QIC Data Cartridge format. See QIC. (2) (Single Lens Reflex) A camera that uses the same lens for viewing and shooting. , and DLT tape formats. While the smaller cartridge size is "sexy" it is a liability when it comes to ultimate data storage capacity. Linear Recording Products: (tracks are recorded parallel with face of longtitudial tape) In linear drives the basic recording technique is similar between TRAVAN, SLR, SC50, and DLT-1 drives (there are variations in recording density/encoding, track pitch, and number of parallel channels). However there are differences in how the tape is handled between the DLT cartridge based drives and the others. The larger recording surface provided by the linear technology drives allows for greater storage capacities in linear products at equivalent data packing densities. Linear recording technique also allows the scaling of data transfer rate based upon addition of recording channels in parallel. It is more difficult to substantially increase the transfer rate on helical formats by addition of parallel channels. Limitations come into play related to relative head to tape speed with helical scan drives where the tape and the head are moving. TRAVAN, SLR, OnStream SC50 utilize cartridges which contain both tape guidance components and a portion of the tape drive system. While this makes for a more complex cartridge, the benefit is the tape drive mechanics required to make use of the cartridge are simplified. An added benefit of this system is less probability of having interchange problems between different drives. In drive styles which fully contain the guidance mechanics in the drive, it is possible to have minor variations in track placement between drives (leading to data interchange problems). The TRAVAN, SLR, OnStream SC50 drives only require one motor to drive the tape, 1-2 actuators to move the head, and one motor to load/unload the tape. The media surface area with these technologies is far greater than either DAT or 8mm drives with SLR style tapes being second to DLT type cartridges in terms of overall recording area. DLT1 style drives use a DLT tape IV cartridge. This type of cartridge provides the ultimate media area (and thus the most storage capacity for equivalent packing density). It does this by filling the entire cartridge "real estate" with tape on one single reel. All DLT style drives require a take up reel located in the drive. This means that DLT drives require two drive motors for tape motion. In addition the tape cartridge See cartridge. contains no tape guidance facility; thus the drive must contain the precision tape path. This contributes additional cost and also is more susceptible to the interchange errors mentioned previously. The take reel in the drive also means DLT1 style products take longer to load and unload To remove a program from memory or take a tape or disk out of its drive. tapes. In a load situation the tape must be threaded through the drive and wrapped around the take up reel, some tape must be wound before tape tension can be established. In unload situations the tape must be fully rewound re·wound v. Past tense and past participle of rewind. back into the cartridge before the cartridge can be removed. These operations take time--more than any of the other technologies. The Benefits Of Tandberg Data Heritage Tandberg Data has been a pioneer in computer data cartridge formats for the last 20 years. They have produced over 2.5 million tape drives based on SLR technology. Their current product range is their second-generation SLR (Scalable Linear Recording Scalable Linear Recording is the name used by TANDBERG DATA for its line of QIC based tape drives. The earliest SLR drive, the SLR1, has a capacity of 250 MB, while the latest drive, the SLR140, has a capacity of 70 GB. ) product family. Tandberg continues to ship SLR drives in high volume (250,000 in 1999). This family uses advanced technologies including VR2 encoding See encode. for additional data density at a given magnetic density, dynamic 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. tracking for additional reliability, shock resistance, and capacity, and an engineering methodology where data formats on tape are created to provide maximum capacity/performance with minimum interchange "baggage". So how is SLR technology positioned to be the new king of the hill in the SMB sector? Take a look at it translated in terms the average user will understand. Price Point: SLR technology, which requires fewer motors and less precision mechanical parts content than helical scan products or DLT type drives, is positioned well for aggressive market pricing. Product Family: In the current environment the user would like to specify a product family which has a future. The SLR product family already has 2 products available beyond the 20GB product category and offers native 50GB/5MB/sec drives today. SLR drives have cost effective autoloader and library technology available today as well. Performance: SLR technology has short media load/unload times, supports partitioning of media for QFA QFA Qualified Financial Advisor QFA Quick File Access QFA Quebec Farmers Association QFA Quoted for Accuracy (internet forum slang) QFA Quinte Film Alternative (Ontario, Canada) directories required by some software packages (just like DAT), and all SLR cartridge formats have special features for improving block seek times. In addition higher capacity drives support automatically adjusted multiple transfer rates, optimizing throughput. The advanced VR2 encoding means greater storage capacity and higher transfer rates with less data channels. Reliability: The current SLR products dynamically adjust recording parameters to insure maximum interchange capability and long service life without problems. Drives have advanced diagnostics and continually demonstrate less than .05% field failure rate. Support: SLR technology has broad software support. All technical documents and current firmware A category of memory chips that hold their content without electrical power. Firmware includes flash, ROM, PROM, EPROM and EEPROM technologies. When holding program instructions, firmware can be thought of as "hard software." See flash memory, ROM, PROM, EPROM, EEPROM and FOTA. images are downloadable off the Internet. Tandberg Data offers toll free technical support as well. Futures: The SLR formats hold other advantages as well, with special features in recording format for tracking media by individual serial number, actual media usage, and media performance, as well as drive performance. Tandberg Data will implement advanced management information features this year that will allow the user to know the "health" of their drive as well as the media they use with it. To Conclude The SMB tape sector is full of alternatives but weigh your choices when it comes to malting malt n. 1. Grain, usually barley, that has been allowed to sprout, used chiefly in brewing and distilling. 2. An alcoholic beverage, such as beer or ale, brewed from malt. 3. See malted milk. v. a selection. TRAVAN NS drives may prove to have too limited a roadmap, are not considered robust enough for serious IT use, and have no automation support OnStream and Ecrix are new tape technologies and although they offer unique features and aggressive pricing their volume success is not assured. The Mammoth mammoth, name for several large prehistoric elephants of the extinct genus Mammuthus, which ranged over Eurasia and North America in the Pleistocene epoch. and AIT products will be difficult to cost reduce to meet SMB market price expectations For DLT1, it will be difficult to match the ultimate price expectations of this market. Although DLT drives dominate the enterprise market space the technology may not scale well. SLR drives, with an installed base of 900,000 drives, 14 years of product advancements, and a "next step" product with 2X the capacity and performance of DDS4 available today, are the logical choice. Gregg Ormsbee is the business development director at Tandberg Data (Simi Valley Simi Valley (sē`mē, sĭm`ē), city (1990 pop. 100,217), Ventura co., SW Calif. in an oil, fruit, and farm region; laid out 1887, inc. 1969. , CA). The editors invite other claimants to the DAT space to make their
Fig 1
Price Point
Model closest to DDS4 parameters-Q4 2000
Drive Model/Maker Drive
DDS-4 Composite $1,083
DLT1/Benchmark Storage $1,199
VXA-1/Ecrix $777
Mammoth-1/Exabyte $2,414
SC50/Onstream $683
AIT-1A/Sony $1,832
SLR40/Tandberg $983
NS20/Tecmar $391
Performance
Drive Model/Maker Media Autoloader Capacity
(Native)
DDS-4 Composite $26.71 $2,691 8/1 20GB
DLT1/Benchmark Storage $66.59 $3,933 7/1 40GB
VXA-1/Ecrix $64 $3,218 15/1 33GB
Mammoth-1/Exabyte $49.06 $5,816 7/1 20GB
SC50/Onstream $41 N/A 25GB
AIT-1A/Sony $74.14 $3,455 4/1 25GB
SLR40/Tandberg $51 $5,301 8/1 20GB
NS20/Tecmar $30 N/A 10GB
Drive Model/Maker Transfer Load Time of
technologies
Rate (Native) relative to DAT
DDS-4 Composite 3MB/sec
DLT1/Benchmark Storage 3MB/sec ++++
VXA-1/Ecrix 3MB/sec +
Mammoth-1/Exabyte 3MB/sec +
SC50/Onstream 500K-2MB/sec +
AIT-1A/Sony 3MB/sec =
SLR40/Tandberg 3MB/sec +
NS20/Tecmar 1MB/sec +
Family range
Highest
Capacity
Drive Model/Maker Access Time drive in family
of technologies available
relative to DAT today (native)
DDS-4 Composite 20GB
DLT1/Benchmark Storage +++ 40GB
VXA-1/Ecrix + 33GB
Mammoth-1/Exabyte + 20GB
SC50/Onstream +++ 25GB
AIT-1A/Sony - 25GB
SLR40/Tandberg ++ 20GB
NS20/Tecmar +++ 1OGB
Highest
Transfer
Drive Model/Maker rate available
rate with drive
today (native)
DDS-4 Composite 3MB/sec
DLT1/Benchmark Storage 3MB/sec
VXA-1/Ecrix 3MB/sec
Mammoth-1/Exabyte 12MB/sec
SC50/Onstream 2MB/sec
AIT-1A/Sony 6MB/sec
SLR40/Tandberg 5MB/sec
NS20/Tecmar 1MB/sec
Fig 2
Technology
Motors
contained in
drive relative to
DAT (adds cost/
Basic Recording decreases
Drive Model/Maker Technique reliability)
DDS-4 Composite Helical 3
DLT1/Benchmark Storage Linear -
VXA-1/Ecrix Helical =
Mammoth-1/Exabyte Linear =
SC50/Onstream Linear --
AIT-1/Sony Helical =
SLR40/Tandberg Linear --
NS20/Tecmar Linear --
Precision
Mechanical
Actuators Content
contained in contained in
drive relative to drive
DAT (adds cost/ (adds cost/
decreases decreases
Drive Model/Maker reliability) reliability)
DDS-4 Composite 2 High
DLT1/Benchmark Storage - -
VXA-1/Ecrix = =
Mammoth-1/Exabyte = =
SC50/Onstream - --
AIT-1/Sony = =
SLR40/Tandberg - --
NS20/Tecmar - --
Leverage
FTPI
Tracks/Stripes less flux transversals
per inch per inch for an
less is better (allows equivalent
for growth by adding capacity are
Drive Model/Maker additional tracks) better
DDS-4 Composite 3,870 122
DLT1/Benchmark Storage --- +
VXA-1/Ecrix - ?
Mammoth-1/Exabyte --- -
SC50/Onstream ---- ?
AIT-1/Sony -- +
SLR40/Tandberg ---- ++
NS20/Tecmar ----- -
Media Area
Data Channels more is better
less channels for (allows for
equivalent additional capacity
transfer at equivalent
Drive Model/Maker rate is better track/bpi densities
DDS-4 Composite 4
DLT1/Benchmark Storage - ++++
VXA-1/Ecrix = +
Mammoth-1/Exabyte = +
SC50/Onstream + ++
AIT-1/Sony = +
SLR40/Tandberg = +++
NS20/Tecmar - ++
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