Tape Wars: Is The End Near?
The Tape Wars coverage in 1999 hasn't been merely the world against DLT--we also explored the other wars for different market segments--those whose primary strength was a low price, others best suited to mid-level requirements, and, of course, the markets served by DLT and drives with similar specs.
During this year, the size of tape drives has continued to balloon. In November 1998, 18GB drives were the new, big thing with a handful of 36GB drives announced, and only one or two 50GB drives being offered. By the end of this year, 36GB drives are available from many vendors with a broader range of 47 and 50GB drives aimed for the mainstream and a number of 72GB drives offered.
Although hard drive manufacturers are making drives of ever-increasing capacities because they can and, although there are serious questions relating to how much data should be put onto one spindle, the production of larger hard drives mirrors the increase in the amount of data being created and stored. The increasing amounts of data necessitate higher capacity, faster backup techniques, and, for many companies, this still means TAPE. Throughout the year, tape drives that meet these needs have been announced or begun shipping. Technology roadmaps hint at the future tape capacities that are being planned.
Fall Comdex, held in mid-November was an opportunity for the drive makers to parade their latest armaments, showing existing products, previewing products about to ship, and discussing somewhat longer-term strategies. A person who knew what to look for would have been able to find these drives embedded into other devices (for example, Ultrium, Super DLT, AIT-2, Mammoth-2, DLT1, VXA, and other future, or just released, drives, which were on display as part of automated tape systems). For this editor, access to private product suites made the process of gathering drive information even easier. Here's what's in store:
Quantum's DLT has been the target of choice for many midrange drive vendors. Although DLT is essentially pretty old technology, its sales have been little short of phenomenal. Since Quantum acquired DLT technology from Digital Equipment Corporation more than five years ago, it has improved the standard and done one hell of a job marketing this product.
A technology like DLT, with origins more than a decade old, has run out of steam. Future generations that are based on the original designs are impractical, if not impossible. Instead, new drives, offering higher performance and higher capacities, while providing read compatibility with existing DLT cartridges, represent the approach that was taken to creating new DLT technologies.
It is not inconceivable that one of the biggest competitors to DLT 7000 and 8000 drives will come from Quantum. The SDLT brings next millennium technology to the new drive. Instead of being a slight redesign of previous DLT drives, the SDLT drive represents a more "from scratch" approach, with late 1990s design methods replacing the 1980s designs in the DLT drives.
For example, the SDLT drive is a modular design. Each of five modules is engineered for easy assembly and easy replacement. The modules are assembled to form the complete SDLT drive.
By making the drive modular, it simplifies manufacturing and servicing--an added benefit is that Quantum can purchase modules from various sources. This multivendor approach helps buffer Quantum from parts shortages should a supplier have a delivery or manufacturing problem. It also enables Quantum to continually improve the drive by modifying a module, while avoiding the necessity of completely redesigning the drive to accommodate modifications.
Additionally, the components that enable the SDLT drive to be read compatible with DLT 4000, 7000, and 8000 drives is one that can be installed on a module--or not. In its first years, read compatibility may be important while customers migrate the data from their legacy DLT drives onto SDLT cartridges. At some time in the future, such backward read compatibility will no longer be necessary. Quantum will be able to offer SDLT drives without the legacy reader components and should be able to offer such drives at a reduced price.
SDLT features a wide range of additional improvements over the earlier DLT. Among these is an improved tape buckling system. In DLT drives, a tape with a broken tab could have been drawn into the DLT drive, resulting in the need for repairs of the drive and removal of the cartridge by Quantum or an authorized repair facility. SDLT drives support a new buckling mechanism for SDLT cartridges and support for existing DLT cartridges. The new mechanism will not load a DLT or SDLT cartridge with a damaged or defective tab.
The SDLT cartridge has been redesigned to meet a number of design goals. The cartridge profile is slightly different from that of the DLT--different enough from DLT that it can't be used in DLT drives, yet physically similar enough that automated tape devices can be easily modified to support SDLT cartridges and drives.
Additionally, the SDLT media has been considerably changed. The major change in first generation SDLT media is the use of an optical servo that becomes part of the tape media during media manufacturing. A low power laser sensor inside the drive that retrieves information regarding tape positioning reads the optical servo. The optical servo is tightly coupled to the drive's recording and playback heads, allowing for extremely precise positioning of the drive's heads relative to the tape.
The use of an optical servo provides an additional advantage: old tapes can be bulk erased, using a device that erases all data on the cartridge. The process can be done in seconds, compared to the minutes or hours that erasing a DLT tape can take. Because the servo signal is optical, rather than magnetic, the servo signal can survive any number of bulk erase cycles. By contrast, if a DLT tape is bulk erased, the process will remove not only data on the tape, but also the magnetic servo tracks that are recorded onto the tape media.
SDLT drives include an infrared send/receive unit that is built into the front of the drive. An optionally available infrared send/receive device can be used to communicate with the drive, obtaining diagnostic and drive performance information. Using software available from Quantum, diagnostic data can be viewed in a browser over the Internet or a company's Intranet.
In many ways, the SDLT drive is a first generation device--from its modular design, redesigned cartridge, and improved tape loading mechanism to its simplified tape path and optical servoing, the drive represents considerable rethinking based on limitations of DLT and anticipated future technology improvements. With anticipated improvements in recording media, progressively finer optical tracks should be relatively simple to write, enabling increasingly higher recording densities in future generation DLT drives.
The first generation SDLT drive will be able to write 100GB native onto a standard SDLT cartridge. The drive has a native transfer rate of greater than 10MB/sec.
Quantum was shipping early units to OEM customers in November. SDLT drives are expected to ship in volume during the late first quarter or some time in the second quarter of 2000.
A few years ago, Quantum engineers set out to develop a DLT drive that was less expensive to manufacture than existing drives that were based on decade old technology. The design featured a simplified tape path and fewer components. The early design was not developed beyond early stages.
Benchmark Data Systems acquired the basic design, and Quantum acquired a percentage of the company. The company built on the basic design, creating what is now known as a DLT1 drive.
The DLT1 drive shares some basic design philosophy with the SDLT drive. A less tortuous tape path simplifies tape loading while improving reliability. The DLT1 drive is read compatible with tapes recorded using DLT4000 drives.
Unlike the SDLT drive, the DLT1 uses magnetic servo signals and DLT cartridges. Benchmark has taken advantage of improved head technologies to produce a drive with 40GB native capacity, and 3MB/sec (uncompressed) speeds. At about $1300, the DLT1 drive can be a strong competitor with many of the midrange drives.
Benchmark has developed its own approach to the tape loading problems experienced by DLT drives, employing a sensor that detects when a tape is successfully buckled to the drive. If the process fails, the tape is ejected, protecting the drive from the costly problems possible with DLT drives. Problems that result from dropping a cartridge or other damage can still occur because the DLT1 uses DLT cartridges (as well as Benchmark labeled DLT cartridges).
Benchmark offers a seven cartridge autoloader, the DLT7, with a native capacity of 280GB and a sustained transfer rate, uncompressed, of 3MB/sec. Additionally, autoloaders and libraries using the DLT1 are already available with more on the way.
The Linear Tape Open Consortium has been working on developing drive specifications and extensive compatibility testing for its two tape formats, Ultrium and Accelis. Ultrium, a clear competitor to SDLT, is the first format to receive the necessary development efforts from the consortium's full members (IBM, Hewlett-Packard, Seagate, and Fujitsu). The current state of development for Accelis by companies other than IBM is unclear.
The Ultrium format specifies a single reel cartridge with 100GB native capacity and native speeds of 20MB/sec. Media will be available with lower capacities, ranging upward from 10GB native. Conceptually, the Ultrium drive is similar to the DLT and SDLT drives. The tape cartridge features a tab at the end of the tape. A buckling mechanism inside the drive buckles with the tab, drawing the tape into the drive and attaching it to a tape reel.
The Ultrium cartridge, while not compatible with any other tape formats, shares a form factor similar to other cartridges, enabling library and autoloader manufacturers to support the Ultrium drives. The drive uses a newly developed multi-track servo that enables writing and reading a large number of data tracks on the tape.
Memory-In-Cartridge (MIC) is available on the data cartridges. The MIC capability enables automatic retrieval of such cartridge data as a file directory, the number of times the tape has been used, and other data. Automated devices may be able to retrieve data about each cartridge by reading the MIC information from the cartridge, instead of having to load the cartridge into the drive and reading the directory.
Because Ultrium drives will be offered by at least four manufacturers, the manufacturers are challenged to create brand identity and loyalty to their particular version of the drive. The LTO Consortium has designated an independent testing lab to verify the interoperability of drives and media across the format. A tape written in an IBM drive can be read by a HP drive, for example. Any certified Ultrium tape will work in any Ultrium drive. Certification will assure cross-format compatibility.
Hewlett-Packard has responded to the name branding challenge by previewing two different Ultrium drives. The most interesting, because it was something of a surprise, is a drive with half the performance of the "standard" Ultrium drive. The low performance reads and writes data tracks that are identical to those produced by higher performance Ultrium drives--it just does it more slowly. Cartridge capacities are the same when used on this drive than when used on higher performance drives--it just takes longer to do. For users whose systems don't support the data throughput speeds of the Ultrium drive or who can't justify the extra cost of the high performance drives, the new, lower performance Ultrium drive may be seen as a good entry-level Ultrium drive.
In spite of product differentiation attempts by the Ultrium drive manufacturers, initially the most compelling sales argument was product availability. At Comdex, third party library and autoloader manufacturers were demonstrating these devices using IBM Ultrium drives. When asked why IBM's drives were chosen, a library maker's answer was clear--the IBM drives were the first available. In the future, when other manufacturers make their drives available, customers may be able to specify one manufacturer over another. For now, IBM, with shipments expected to begin in early 2000, will be the, early winner. IBM and Hewlett-Packard are expected to be shipping drives early 2000 with IBM beating HP to market.
With assured compatibility, product differentiation will be very important to all Ultrium vendors. Competition between them can produce interesting variations such as the lower performance drive announced by HP, for example. Competition may also help force, or keep, prices down--especially so after initial demand for the drives is met. With many IT organizations taking a wait and see attitude even after the first drives ship ("let someone else be the guinea pig"), demand may start slowly, with single drives bought for testing and validation, followed by a move to multiple drive systems, libraries, and autoloaders. Initial demand may ramp up at nearly the same rate as drive production.
If the competition between Ultrium makers keeps prices below SDLT, Ultrium may also force SDLT prices downward. The competition may be good for the industry, if not for the drive maker's profit picture.
Exabyte's Mammoth-2 drive is the latest enhancement to its 8mm Mammoth product line. The Mamoth-2 supports a native transfer rate of 12MB/sec and an uncompressed capacity of 60GB per cartridge.
Mammoth-2 (M2) is an 8mm helical scan drive with a number of evolutionary features, according to the company. The scanner (which interfaces the read/write heads to the drive electronics) is said to be larger than the scanner on DDS and AIT drives. The M2's scanner accommodates four read/write heads and has embedded the scanner electronics directly on the heads. This new design improves the signal/noise ratio and is said to enable increased bit density and higher drive performance than other available drives.
M2 was designed to simplify automation, using a form factor that is similar to the Mammoth and that requires little or no modification in order to make the drive compatible with tape libraries or autochangers. In recent years, Exabyte has become a significant player in the automation business, providing both DET-based libraries, as well as Mammoth-based libraries. The M2 will become the core of future, higher performance and higher capacity libraries.
A library equipped with an M2 drive is said to deliver the highest rack mount density in the industry and as much as three times the density of existing DLT tape products in the same footprint, the company claims. However, at the time that this claim was made, neither SDLT nor Ultrium drives were available. However, the 60GB native capacity of M2 tapes will probably still deliver considerably more density than the larger SDLT and Ultrium cartridges, when the comparison is made strictly on the number of terabytes of media can be placed into libraries of the same size.
The M2 cartridge has a unique self-cleaning feature, which Exabyte calls SmartClean. A special leader on the M2 cartridge automatically cleans the drive heads when it is inserted, or when the drive electronics determine that the heads need cleaning. Exabyte claims that this feature will reduce system down time while increasing head life. A large (and, by comparison to other drives, it really is large) 32MB buffer can improve performance by smoothing mismatches between the data transfer rates of the drive and the computer being backed up or restored.
The M2 drive is backward compatible with Mammoth media. The drive, with a starting MSRP of $4895 for an internal unit, is now available.
Sony's AIT-2 has been shipping for a few months and represents Sony's top-of-the-line 8mm drive offering. The drive features 6MB/sec native data transfer speeds and the tape cartridges have a native capacity of 50GB. The AIT-2 has an 8MB buffer.
Media with native capacities of 25, 35, 36, and 60GB native capacity are offered by Sony. The AIT-2 drives have been seen in an increasing number of libraries and are also important in various environments. With their native 50GB capacity, the drives can store more than other drives available at the time the AIT-2 was announced. With the release of M2, SDLT, and Ultrium, the AIT-2 drives will take a number 3 position in terms of native capacity. Still, with a form factor similar to that of the M2 and a tape capacity that is about 80% as large as the M2 (50GB, compared to 60GB), the AIT-2 drives, also an 8mm drive, should have little problem maintaining market share.
Additionally, the AIT-2's MIC (Memory In Cartridge) capability can be very attractive, particularly to automation vendors. MIC stores information about the tape cartridge--contents, number of times it has been inserted, etc., that can be quickly and easily read by the automation device. Moving the sensor over the cartridges and reading the MIC information can easily and quickly catalog the contents of a library. By contrast, other libraries use bar code readers and rely on a database in the server to maintain basic information about the data on the cartridge, or, worst-case, each cartridge must be loaded into a drive and read in order to have basic data about the cartridge contents determined. Additionally, the information stored by MIC may help determine when a tape should be retired before any media problems develop. MIC or similar technologies are planned for other tape formats.
SLRl00 is a linear tape format (as opposed to helical scan) developed by Tandberg Data. The new drive features a native capacity of 50GB and a native transfer speed of 5MB/sec. The drive features an 8MB buffer.
The SLR100 has a number of interesting features. Perhaps the most interesting is the use of Variable Rate Randomizer (VR2), a technique developed (and licensed from) Overland Data. VR2, previously explored by Computer Technology Review, is an improved method of organizing and writing data to linear tape that both increases native capacity and improves the data transfer rate of drives equipped with the technology.
The SLR100 features a variable data transfer rate with what they call "auto-sense." This allows the drive to detect the actual data transfer rates of the connected computer and to adjust the tape drive so that it is in synch with the computer. This reduces the need to interrupt the data transfer in order to synchronize data coming from (or going to) the computer to the position of the tape. In theory, this reduces the wear on drive components, which won't have to do as many stops, rewinds, and fast-forwards in order to reposition the tape and bring it up to recording speeds.
The SLR100 is backward read compatible with SLR50, SLR32, and SLR24 drives. The drive was announced in November. Ship date and pricing were not available at press time.
Ecrix's VXA-1 drive has applied some new thinking to 8mm tape drives. VXA-1 media comes in two sizes with native capacities of 33GB or 12GB. The drive has a sustained data transfer rate of 3MB/sec and features a 4Mbit buffer.
Ecrix has done a number of things differently from other drives. The main difference is the use of what Ecrix calls Discrete Packet Format to write data. Data being written to the tape is written in 64 bit packets. Each packet includes error correction data, as well as a unique identifier.
A data buffer is filled with 384 packets, which are arranged in a specific order, based on packet address. Error correction routines programmed into special ASIC chips can repair damage to any missing or erroneous packets. Error correction is performed vertically, horizontally, or diagonally when each data buffer is filled, thus allowing three different levels of correction to be implemented and assuring a high degree of accuracy.
Each data track will be read by at least two heads (Ecrix calls this technology Overscan) because the drive has four heads. The theory is that, if one head misreads the data, the second head may read it. Through the use of Discrete Packet Format and sophisticated error correction, the need to re-position the tape so that it can be reread is significantly reduced.
VXA drives also have motor speed control, providing the ability to transport the tape at any of four speeds. This is important if the speed at which data is transferred from the drive to the computer is mismatched--for example, if the computer is sending backup data to the drive more slowly than the drive is operating, the drive can slow the tape motion to a speed that is more closely matched to the computer, thus eliminating the need to stop and start the tape in order to smoothly record data.
VXA drives are currently available in internal and external models. A number of automation vendors are also offering changers and libraries using VXA drives.
Ecrix has made a major push to qualify the drives for use with Linux in addition to their use under Microsoft-developed operating systems. Pricing for VXA-1 drives begins at under $1000.
The DDS format has been around for a long time (though not as long as DLT). DDS is a 4mm format that originally shared many of the drive mechanics with the DAT (Digital Audio Tape) drives. When DAT first became available for data backup, a variety of incompatible formats were available, effectively tying a user into a single vendor's product.
Ray Freeman of Freeman Associates, a consulting group in Santa Barbara, CA, spear-headed efforts to bring order out of the situation and DDS was developed. DDS has gone through a number of iterations, the latest being DDS-4.
Both Sony and Hewlett-Packard offer DDS-4 drives at the time this is written. Seagate and other vendors offering DDS-3 drives have been unclear about plans for DDS-4.
DDS-4 drives accommodate media with native capacity of up to 20GB. Data transfer rates may vary slightly from one vendor to the next. The Sony DDS-4 drive has a native transfer rate of 2.4MB/sec. Full backward compatibility to earlier generation DDS media is part of the DDS specification.
Hewlett-Packard's DDS-4 drives include a feature called One Button Disaster Recovery (OBDR), which can store the data necessary to restore the NT operating system to the computer on which it was created. After a disaster (a hard drive crash, for example), the DDS-4 drive can be set to appear to the system as if it was a bootable CD. The data can be read from the DDS-4 drive and reinstalled onto the damaged hard drive. A second boot restores the operating environment.
The DDS-4 drive is primarily intended, for PC backup or for organizations that don't need the high capacity and blazing performance of high-end devices. DDS-4 drives will be available with autoloaders, installed into NAS devices and as internal or external drives for PCs or PC-based servers.
In addition to the drives listed above, a few other technologies should be noted. OnStream, like Ecrix and Benchmark, a relative newcomer to the drive business, features an interesting streaming technology that uses eight channels, writing simultaneously to the tape, in order to write and read a reliable data stream.
The original offerings included models with native capacities of 15 or 25GB and both SCSI and ATAPI interfaces. A new model, the ADR70, features a 35GB native capacity. All drives have a native transfer rate of 2MB/sec. The ADR70, with a list price of $999, is available as an internal drive with an Ultra2 Wide LVD interface. Shipping is planned for 1Q 2000.
The OnStream drive is said to be selling very well because of its relatively low price of around $20 per native gigabyte capacity. Additionally, software provided with the drives is said to perform streaming, real-time backups. A demonstration by OnStream at a trade show earlier this year showed real-time playback of MPEG video streaming directly from an OnStream drive. The capability to continuously stream data without the necessity of stopping and repositioning tape, while also retaining synchronization with the attached computer provides a strong argument for the ability to continuously stream data during backup or restore.
Travan has been around, in a number of capacities, for many years. Having evolved from Quarter-Inch tape, Travan has provided a standard for relatively low capacity, moderate performance tape drives, primarily aimed at consumer and small office users. The current generation, which offers optional capabilities that are an attempt to position it for NT systems and network backup. These features include motor-assisted insertion and ejection of the cartridge and a stronger design.
The latest iteration, TR-5, is fully backward compatible with earlier Travan media. TR-5 features 10GB native capacity and 1 Mbit/sec native data transfer. Travan drives are available from a number of vendors, including Tecmar, Hewlett-Packard, and others. However, when compared to such devices as those at the top of this article, it is clear that Travan's primary target is for the home user or small office with considerably lower capacity and performance requirements than the organizations considering SDLT, Ultrium, M2, and other devices.
The growth of data capacity and the increasing amount of data that must be stored, backed up, and (gulp) occasionally restored has necessitated a range of tape products, both stand-alone drives and automated systems, that are up to the task. In this article, we've discussed the major players in the ongoing Tape Wars (no, the war is nowhere near over), and given a peek at what we'll be seeing in the coming year(s).
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|Title Annotation:||Industry Trend or Event; tape drives|
|Publication:||Computer Technology Review|
|Date:||Dec 1, 1999|
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