Your storage options today...........................
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Secondary storage is an ever-more evident imperative in today's data-deluged computing world, and just which secondary storage option is most appropriate depends on what the user intends to do with the extra capacity it offers. I'll never forget my first hard drive, a Seagate ST 225, which I bought ten years ago. Its specs--hearkening back to a bygone computing era--speak for themselves: packing a cavernous 20MB of storage capacity in a svelte, 5 1/ 4-inch half-height enclosure, My First Hard Drive (henceforth MFHD) carried a bargain-at-half-the-price cost of $300. The torch I still carry for MFHD is not entirely lit by sentiment; while not the largest hard drive available for a PC at that time, or the smallest, its capacity and performance specs were roughly industry standard a decade ago, and the Seagate was either the most or least reliable storage device ever built, depending on whom you ask.
From the 20MB dinosaurs of yesteryear to today's 2GB and beyond behemoths, most users depend on hard drives as their primary storage device. Hard drives are cheap, reliable, fast, and therefore well-suited to holding a computer's operating system, applications, and dynamic data--the files created using spreadsheets, word processors, databases, graphics, and other application programs.
But what was a small file yesterday can be a immensely larger one today. The need for secondary storage has become acute. The text of a 3,000-word magazine article, for instance, takes up about 21KB as ASCII characters. But in Microsoft Word 6.0 for Windows, which embeds formatting commands and other "invisible" characters, it consumes 37KB. Spruced up a bit with, say, ten minutes of background music recorded in CD-quality 44.1 KHz, 16-bit, stereo .WAV file sound, and ten minutes' full-motion video of comparable quality, plus ten-color bitmap graphics representing supporting charts, then this "article" file would bloat far beyond the capacity not only of a 1.44MB floppy disk but even, possibly, a 100MB Zip cartridge.
I exaggerate, but not by much, since real-world work has placed increasing demands on storage systems. Managing the document images in, say, a human resource information system can easily go beyond an employee's work history to include files representing signatures, photographs, and medical records-- all the kind of imaged material that can eat up storage capacity with alarming rapidity.
And just as my own need for secondary storage space keeps going up, so too--if I want to distribute my files--do the storage needs of my target distribution audience. They will have to have larger-capacity storage devices, and specifically, they will need devices that are compatible with mine, so they can read the media that I ship to them.
But it's not only the files we develop, but the application programs and operating systems themselves which have grown as well, in the past ten years. Word for Windows 6.0, fully installed, eats up about 25MB, whereas Wordperfect 5.1 for DOS needed only one-fifth the space and could be delivered on five floppy disks. Windows 3.1 commandeered 10 to 15MB of disk space, while Windows 95 gobbles 25 to 40MB. Many modern programs contribute to the problem through an undocumented proclivity to write--but never erase--large temporary files. And even when supposedly uninstalled, most applications today fail to delete themselves fully.
So secondary storage is an ever-more evident imperative in today's data-deluged computing world, and just which secondary storage option is most appropriate depends on what the user intends to do with the extra capacity it offers. You could, of course, add terabytes of storage by piling on thousands of 1 and 2GB hard drives; however, even with the swift 9 to 12ms access times today's leading hard drives deliver, their efficient interfaces, and relatively crash-proof performance, hard drives are not ideal secondary storage devices. For one thing, paradoxically, they aren't really big enough. Those who work with audio and video, or with large databases, have disk space needs that far exceed a gigabyte or two. A/V files comprised of raw audio, .WAV, .AVI, QuickTime, or MPEG data all gobble disk space quickly. So too do many of the large-scale but otherwise conventional applications, such as document image management.
Also, if you need to distribute your data to other people, it's hard to transport a hard drive, even one that's externally enclosed and ostensibly easy to plug into a SCSI connector. Just because another computer has a SCSI controller card inside, there's no guarantee that it will also have the necessary software drivers, or the ability to recognize the way the drive was originally formatted.
So for secondary storage, removable media represents the best solution. Replacing one disk with another multiplies the capacity of a single drive almost infinitely. Removable magnetic disk systems enjoy their current popularity because the drives are comparatively low-priced, they offer almost hard drive-like seek-times and data transfer rates, and they're available in convenient capacities.
Removable optical disc systems, while slower than their magnetic counterparts at any given capacity-point, offer the random access to files that tape cannot, lower cost-per-megabyte than hard drives, and arguably the highest level of physical stability. Both write-once and rewritable optical media can maintain data intact for decades. From 3 1/ 2-inch magneto-optical (MO) drives to 14-inch write-once/read many (WORM) units, and the various flavors of CD and DVD in between, even in the face of environmental hazards, it's very hard to spoil an optical disc, which only adds to the already compelling arguments for optical media devices as the optimum choices for secondary data storage.
Few prospective customers take the time to consider the storage options, but it's worth the time it takes. Most people don't buy a car without first checking the ads, reading the product literature and comparison-test articles, talking to several sales people, and then test-driving. Why should a company with growing needs for efficient data storage make a comparably large investment with less information?
MAGNETIC MID-LEVEL DISK STORAGE: A TWO-HORSE TOWN
In the removable magnetic storage media category, the battle for predominance pits two competing factions, Iomega and SyQuest, who have been matching each other nearly product-for-product for nearly a decade. Each has, at some point, leapfrogged over the other's products with something new, and there is no evidence of a truce in sight.
The staple steed of the Iomega stable is the Zip drive, a practical and inexpensive secondary storage medium, that enjoys a great deal of popularity in the industry, despite its relative dearth of capacity compared to 650MB CD-Recordable, 2.6GB MO, and the like. But Zip drives compensate for their storage shortcomings with their easy removability and cheap drive and media costs; the drives, which are available in both parallel and SCSI configurations, list for $149, and disks are about $18 apiece. Because Iomega has marketed Zip to such a high level of visibility, its large installed base makes Zip cartridges a good choice for exchanging over a "sneaker-net," and many graphics-oriented businesses, such as store-front desktop publishers, are equipped to accept and use files stored on Zip disks.
Going toe to toe with Iomega's Zip drive for mid-size magnetic removable storage supremacy is SyQuest's EZFlyer 230, which holds 230MB in a removable hard-drive cartridge. It's faster than Zip too, with a 13.5ms access time, and is also available in both parallel and SCSI versions. The EZFlyer lists for $299; the cartridges sell for $29.95. EZFlyer faces tough competition at the low end from Zip, from magneto-optical (MO) drives at the same capacity point, and from the higher-capacity Jaz and SyJet drives. But if 230MB is enough for what you need, EZFlyer makes a relatively inexpensive, low-maintenance choice.
Iomega also offers the somewhat higher-end Jaz drive, a 1GB removable hard drive, which is better suited for audio and video work than its Zip stablemate because of its greater size and faster performance. Jaz drives have a SCSI interface and list for $399 (internal) and $499 (external). However, the media cartridge is expensive--it lists for $99--which is likely to be a strike against it in the market, particularly stacked up against 2.6GB MO media, which offer significantly greater capacity for a slightly lower price, typically selling for $75 to $85. Iomega has recently partnered with network and tower server manufacturer Axis Communications to offer the Axis StorPoint HD for Jaz, which puts the Jaz drive out on networks in a four-drive tower, complete with Axis' StorPoint storage server. The StorPoint HD for Jaz implements a compatible, multiplatform workgroup storage server, allowing users in Windows NT, Windows 95, OS/2, and other environments to write to and read from any drive connected to the network, and gives a sense of the corporate, network-connected target audience Iomega is increasingly pursuing for the Jaz drives as secondary storage devices.
SyQuest's slightly newer SyJet also makes a slightly better bargain: though technically similar to the Jaz drive, SyJet beats its capacity by a third, offering 1.3GB of removable storage. SyJet is available with several interfaces, listing for $399 for the internal IDE model, $499 as an internal SCSI drive, and $550 in the external parallel configuration designed to add mobile storage capacity to portable PCs. Cartridges cost $125, which makes their cost-per-megabyte index roughly equivalent to Jaz media--i.e., on the expensive side. But considering the extra capacity of SyJet versus Jaz, with the two drives essentially the same price, SyJet may take the larger market share.
And where is that market? SyJet and Jaz aren't corporate staples yet; they're too new, and they're targeted at the single user or small business operator who buys storage devices in the retail aftermarket. And while the Axis Jaz tower represents one attempt to make more storage available, prospects for jukeboxes that incorporate SyJet and Jaz drives are less promising because the cartridges were not designed to be machine-handled, and because the drives require a securing action following insertion, which is beyond the ability of current jukebox robotics.
MO FASTER, MO BIGGER, MO MONEY: IS MAGNETO-OPTICAL TOO EXPENSIVE TO CHALLENGE CD?
Magneto-optical (MO) drives have been around for years, and enjoy great success in large enterprises, mainly because they have been so successfully integrated into jukeboxes. The amount of corporate data they hold probably exceeds that of every other medium except the original IBM 3480/90 tape cartridge format. Also, most MO manufacturers have maintained backward compatibility: new drives can read all previous generations of disks, and can write to media that's at least two generations old.
But MO manufacturers have never managed to sell the drives cheaply enough to penetrate the PC market. Prices have come down of late, especially for 3 1/2-inch drives, but MO still faces a challenge in commanding the type of mainstream attention to magnetics that Zip has engendered.
A 640MB, 3 1/ 2-inch MO drive lists for $599; a 230MB drive for about $299; and there are portable versions of the 230s available for about $100 more. MO media is quite cheap: the 640MB disks sell for less than $15, the 230MB disks cost less than $10. That makes MO a fair competitor against the lower-priced magnetic drives with their much higher-priced media. And MO drives are fully backward-compatible, meaning the 640MB drives will also read and write 230MB and the original 128MB disks as well. This makes 3 1/2-inch MO a very flexible choice: users can pick the disk that suits each need.
Among Fujitsu Corporation's many optical storage drives and media and ancillary products are a number of MO drives in the 3 1/2-inch form factor category that offer up to 640MB of storage per disk. Fujitsu produced the industry's first 1-inch high, 3 1/2-inch form factor drive device. The latest generation of Fujitsu MO drives read, write, and rewrite 3 1/2-inch media at both 640MB and 230MB capacity. The drives are also backward-compatible with 128MB disks in read-only mode. The Fujitsu DynaMO 640 lists at $449, and DynaMO disks sell for under $25.
MO also comes in a larger, 5 1/4-inch form factor. The de facto industry standard is a capacity point of 2.6GB for double-sided media, with 1.3GB of storage capacity on each disk side. 5 1/4-inch MO drives have the laser head and the electromagnet on opposite sides of the media; so the user (or, as the case may be, the jukebox's robotic arm) must flip the disk over to access both recording surfaces.
Some MO drives come close to hard drive access times of a few years ago, but still cannot match the seek time of a contemporary hard drive. The Maxoptix T4-2600, for instance, is a 2.6GB drive with a 39ms seek time. The internal model of the T4-2600 costs about $1960; cartridges sell for $70.
Another new 5 1/4-inch form factor 2.6GB MO drive is Nikon Corporation's Beluga AV, which uses direct-overwrite technology pioneered by Nikon for enhanced speed and ease of writing/ rewriting. The company claims 4MB/sec sustained read and write data transfer rates for the drive, and a burst transfer rate of 10MB. A 6-drive tower called the Array is also available from Nikon. Plasmon's new DW260 2.6GB direct-overwrite-capable drive sells for $1995, with cartridges available for $85 (non-direct-overwrite-capable) and $99 (direct-overwrite-enabled).
Hewlett-Packard, a mainstay of several optical storage markets, including CD-Recordable and CD-Rewritable, offers one 5 1/4-inch MO drive, the 2.6GB SureStore Optical 2600fx. The SureStore Optical reads and writes 2.6 and 1.3GB optical disks, and offers backward compatibility with smaller-capacity 650 MB disks. The 2600fx boasts a 35ms average seek time and its transfer rates are 3.4MB/sec for reading and 1.7MB/sec for writing, helped by an internal read/write buffer.
One MO manufacturer, Pinnacle Micro, makes a 4.6GB drive, called Apex, that lists for $1,395 (external) and $1,145 (internal), but its media, which sell for $99 per cartridge, cannot be used in other, industry-standard 2.6GB MO drives. Pinnacle also offers a 2.6GB MO drive called the Vertex. The Vertex is based on Pinnacle's own optical mechanisms, and features a fast rotational speed of 3755rpm, a 19ms seek time, and a data transfer rate of up to 4.3MB/sec. The Vertex--whose pricing just dropped to $995 for its internal version, making it the first sub-$1,000 2.6GB MO drive--is also available in an external version, which sells for $1,199. Pinnacle 2.6GB MO media are available for $69 each.
Since each MO disk side holds at least as much data as a gigabyte-plus hard drive, and the software available for use with the drives is well-developed and efficient, MO drives make ideal backup and archiving devices. And you can boot from an MO drive, which enables you to restore your system after a disaster. If the initial cost of the drive doesn't scare you away, MO--whether 3 1/2-inch or 5 1/4-inch--can prove a shrewd and rewarding investment.
HOW WILL THE WORM SURVIVE? SECURITY AND CAPACITY
Still a popular storage medium in high-end document imaging systems, 5 1/4-inch write once/read many (WORM) drives never took hold in the consumer market. Their limitations are considerable: high-cost hardware--typically $2,300 or so per drive; middling access speeds--about 45ms; and of course, the inability to erase or rewrite data. For some applications--particularly those that have legal or regulatory requirements for data permanence--WORM systems are still manufactured and deemed indispensable by users for whom security and permanence are paramount.
The most famous application for WORM discs is the drug-approval process at the U.S. Food and Drug Administration. In the early 1990s, the FDA was unwilling to standardize on (and thereby favor) one 12-inch WORM manufacturer's system over another. Instead, the agency has maintained systems from all four major vendors, and the drug companies simply send their research data and other relevant findings on whichever disc format that company happens to use. The justification for using 12-inch WORM despite high attendant costs has always been and remains its enormous capacity--which other devices have only begun to challenge quite recently--and, of course, the absolute indelibility of the data.
Panasonic's LF5300 is one example of a WORM drive, a 1.4GB model that lists for about $2400. On the higher-end, some WORM drives offer voluminous storage capacity via 12- and 14-inch optical platters. The Sony WDD-931 WORM drive, for example, provides up to 6.55GB of storage capacity in a 12-inch disk format. The WDD-931 is available in a standalone drive configuration or a standard 19-inch instrument for rack mounting. Sustained data transfer rate is advertised at 900KB/sec and 4.0MB/sec can be achieved in burst mode, according to Sony, through synchronous transfers. The WDD-931 has 8MB of RAM and includes a 64KB read-ahead cache designed for use in sequential reads of small files. Average seek time is 180ms.
The Philips Laser Magnetic Storage Series 4000 family of 5.6GB 12-inch WORM optical disk drives have dual head read/write performance and are designed for fast response and throughput in demanding data access-intensive environments. The new Philips Infinity 6000 family of 12-inch optical mass storage products provides double the disk capacity--12GB--and four times the data transfer performance of the 4000 series.
SO LIKE CD BUT NOT CD: WHY PD WAS OVERLOOKED
One of the most interesting and versatile but least-understood storage solutions is Matsushita's Phase Change Dual (PD) drive. Branded by Panasonic, Plasmon, NEC, and Toray, PD reads and writes proprietary 640MB disks that are the same size as CDs; and it also reads (but does not write) CD-ROM, and CD-R media. Prospective users were initially confused by PD's similarity to other optical systems, especially CD-R; but the vendors did not adequately explain the difference, nor, arguably, did they market it aggressively.
PD uses phase-change optical technology, which differs from MO in that it doesn't employ magnetics at all: both the reading and the writing are done with laser light. And whereas CD-R is a write-once system, PD is rewritable. PD drives are slower in their seek times and data transfer rates than are hard drives: 165ms and 900KB/sec are typical benchmarks for PD drives, which makes them less than a tenth as fast as today's common hard drives. PD drives, available in both internal and external versions, with both SCSI and parallel interfaces, typically cost around $399, with compatible media pricing at about $50 per cartridge.
The most recently released PD model is a new 6X version of Toray Optical Storage Solutions' Phasewriter Dual (PD) drive. The drive combines 6X CD reading capability with the ability to write and rewrite 650MB PD cartridges. Marketed as a low-cost, removable, rewritable backup and storage device, the 6X Phasewriter Dual ships with either SCSI or SCSI-to-Parallel adapters, Seagate Backup software for Windows 3.1, Windows 95, and Macintosh, and one 650MB PD cartridge, and lists for $349. Both Plasmon and Panasonic also sell PD drives in jukebox configurations for higher-storage and network back-end applications.
PD is a useful product, and potentially well suited to be a "development system" for CDs; but no one has yet found a killer application for PD that can overcome the inherent advantage of CD-R: that practically every computer has a CD-ROM drive that can read virtually anything written to CD-R. Where PD may earn some overdue cachet in coming months and years is with the predicted market insurgence of DVD-RAM, the current standard for rewritable high-density CD. Based on the same technology used in PD drives, DVD-RAM drives will be essentially 2.6GB PD drives, which will have backward-read compatibility with PD media but not with CD-R or CD-RW. Depending on the success of the new DVD-RAM market, PD may soon find itself playing in places that CD-R and CD-RW never will--or at least not anytime soon.
APPROACHING THE LIMITS OF CD: RECORD & REWRITE
The hottest thing in secondary storage today is the recordable compact disc (CD-R) and its new variant, CD-Rewritable (CD-RW). On a downward price trend for ten years, CD-Recordable drives cost more than $100,000 in 1989, but can be purchased today for as little as $299--complete with an interface card, cables, and a couple of pieces of blank media.
But CD-R has some severe limitations. The original compact disc, on which the entire subsequent CD technology family has been based, was never designed to be a recordable medium. It's really a linear medium. A single track of data spirals out from the center, like the groove in a vinyl phonograph record. As adapted into CD-R, CD requires files to be manipulated or formatted in certain ways before they can be written, and can only be added after the previous entry. This restriction has proven problematic and confusing for many an end-user. CD-R is retrograde in other ways. An originally advantageous industry standard for file formatting, CD-ROM's standard ISO 9660 file system allows a CD-ROM or CD-R disc--no matter on which computer it was developed or recorded--to be accessed by practically every other computer platform. But the same standard also requires that CDs employ the lowest common denominator for file names: the DOS-dictated "eight-dot-three" scheme. This is a limiting factor for users accustomed to the extended file-naming conventions in UNIX, Macintosh, and Windows 95 and NT operating systems.
Recently, software workarounds have overcome some of these limitations. In 1996, the Optical Storage Technology Association (OSTA) approved the Compact Disc Universal Disk Format (CD-UDF), a logical file format that is better suited to small file sizes, and thus gives CD-R more of the flexibility available in other storage media. Adaptec's new Direct CD is an early implementation of "packet writing," a new method of writing to CD which allows the user to copy data transparently to CD-R as if it were a hard drive.
"Drive letter access" is the quasi-official buzzword for this enhancement. It means simply that the CD recorder appears to the operating system as yet another drive identified by a letter (D:, E:, F:, etc.) or drive icon, and that any program that can write files to a hard drive can write them transparently to the CD-R disc. This capability strips away the frustration and volatility of recording an ISO 9660 disc image on-the-fly. It's likely that subsequent products will go even further to make CD-R resemble just another drive; in any case, many new CD-R users will probably not encounter the vagaries of ISO 9660 and its arcane file-naming conventions.
CD-Rewritable (CD-RW) is another attempt to overcome CD-R's write-once rigidity and bypass the native CD dilemmas. This new rewritable technology, widely supported in the industry, is now available in drives manufactured by Ricoh and Philips, and sold by various VARs, including Pinnacle Micro and Hewlett-Packard; other manufacturers, including Yamaha, with its forthcoming 4X write/2X rewrite/6X read drive, will soon follow. CD-RW drives come at an attractive price: Ricoh's MP6200S CD-RW lists for $699, while Philips' Omniwriter debuts for $799, both only about $100 to 200 above the suggested retail prices of today's CD recorders.
CD-RW uses the Compact Disc Universal Disk Format as its logical format, but unlike CD-R, it uses phase-change technology like PD, to enable files on CD-RW media to be rewritten or erased, not merely hidden from the directory structure, as is done in the write-once CD-R. But CD-RW has some drawbacks. CD-RW drives can write CD-R discs, but CD-RW discs can not be read by most of today's CD-R or CD-ROM drives. To do that requires the new "Multiread" capability, which is only now appearing as a feature on new drives, such as Plextor's 12X/20X CLV/CAV drive and TEAC's 24X CD-524E; those drives that have this CD-RW read capability will carry the Multiread logo.
As multiread drives increasingly become the norm over the vast installed base of CD-ROM--and, already, at least a dozen new CD-ROM drives are multiread-capable--CD-RW could overcome consumer resistance to recordable CD as a secondary storage medium, and sweep market share away from competing technologies. However, while the hardware technology is here now, software support is not yet mature. The current version of Adaptec's Direct CD--now packaged with most CD-RW drives--will erase an entire CD-RW disc, but not any specific file or files. The other variable-length packet writing tools on the market, Smart Storage's FloppyCD, CeQuadrat's PacketCD, and Adaptec's Mac-only ToastDirect, also lack this feature. Direct overwrite capability is promised in subsequent versions of Direct CD and others, but until it arrives--and is a seamless procedure from the user's point of view--CD-RW will not resemble a truly rewritable random-access optical disk system like MO or PD.
SECOND-GUESSING SECONDARY STORAGE: TOO MANY ATTRACTIVE OPTIONS, TOO LITTLE DIFFERENTIATION?
The choices available for secondary storage today are manyperhaps too many. Choosing the right one for your specific needs is hard. And the hardware and the consumables represent a major investment no matter how big or small your computer system may be, just as My First Hard Drive (MFHD) was a big investment for me ten years ago.
Much has changed since then; perhaps the most cataclysmic change--or at least the one that may somewhere down the line do the most to set the world of secondary storage on its ear--came when CD-R was adapted to what had previously been read-only tower configurations; and then, about two years ago, when software developers perfected the ability to do writes in one jukebox drive while other drives were reading. This achievement opened the door for CD-R--already the most widely interchangeable of all storage media--to join optical disks and cartridge-based magnetic tapes in commercial storage systems. Since users don't need a writing drive to read CD-R media, and since there's a CD-ROM drive in practically every computer nowadays, CD-R has emerged as an outrageously cost-effective means for distributing data, and probably now has the greatest upside potential of any storage device in the marketplace.
But CD-R, for all its best-of-many-worlds advantages, is not one of the higher-storage offerings currently available across the secondary storage market's broad landscape; and even at 40 times the capacity of MFHD, CD-R's 650MB ceiling remains well below the needs of many users, as evidenced by the ongoing sales performance of 2.6GB, 4.6GB, and 12GB devices, as well as the clamoring for CD-R's fellow CD offshoot, DVD. Perhaps, ten years from now, users will be contemplating the various ways to store a terabyte of data, and perhaps for under $500; maybe a few of the choices will be based on a technology that's only theoretical today. But probably, you'll still be confronted with a huge list of acronyms--some yet to be coined--and it's likely that you'll long for the day (at that point twenty years in the past) when the choice boiled down to something as simple as--and only now, absurd-- "Should I buy a 20MB drive or stretch my budget and get 30?" |
