Options abound for agencies that need storage for small to midsize groups of networked PC users as vendors enrich the different storage media with new technology and features. Magnetic disk storage remains the predominant solution for workgroup storage because the response time is superior and the
Options abound for agencies that need storage for small to midsize groups of networked PC users as vendors enrich the different storage media with new technology and features.
Magnetic disk storage remains the predominant solution for workgroup storage because the response time is superior and the technology is affordable if the storage volume is not too great.
But there is a blurring of distinctions between media, as optical and tape drive vendors incorporate technology to increase access time on these media and position their products as disk alternatives. And vendors of all three storage solutions have bolstered their offerings by introducing storage management software typically associated with higher-end storage solutions.
There's a degree of confusion among users because of the sheer number of choices, according to Dhaval Joshi, a research analyst with Doculabs Inc., Chicago, which advises government users on technology alternatives.
Users need to consider expected storage volume, data retention policy, the frequency with which they anticipate accessing different types of data and projected growth over the foreseeable future, Joshi said. A common mistake, according to Joshi, is to get the right solution for today but not for tomorrow.
Small Workgroups Opt for Disks
As always, small workgroups generally gravitate to multiple magnetic disks, sometimes equipped with Redundant Array of Independent Disks (RAID) technology for better fault tolerance and performance.
For example, the Labor Department's Employment and Training Administration, with 1,600 employees, uses an optical jukebox to store about 60G for less frequently required files, but otherwise ETA relies on RAID disk storage for workgroups, said Pete Brunner, chief of the agency's Automated Data Processing Management Division. The administration's workgroups range in size from six to 170 users.
At the National Institutes of Health the story is much the same. "We absolutely use disk," said Perry Plexico, chief of NIH's Computing Facilities Branch, Bethesda, Md. "It's very inexpensive and much more effective" in access time than tape or optical drives. NIH workgroups can range from a few people to a few hundred people, he said.
The Federal Deposit Insurance Corp., at a 100-user site in Kansas City, Mo., likewise employs magnetic storage for personal files and shared off-the-shelf applications, said Pat O'Connor, a computer specialist in the agency's Division of Information Resources Management.
In a reverse to the data aggregation trend, however, certain applications are being offloaded back to local workstations, he said. Word processing, for example, which can tie up network bandwidth with spell checking, is moving back to the desktop. Server storage is RAID-configured, and tape is used only for backup purposes.
Many agencies use RAID for high-availability online storage needs. Users can configure disks in a number of RAID configurations, depending on their specific performance and availability requirements.
Hewlett-Packard Co. recently introduced a product called AutoRAID, which automatically adjusts the RAID configuration to optimize a storage system for performance and availability, said Milt Weatherhead, a sales program manager with HP 's Government Business Unit, Falls Church, Va.
AutoRAID-equipped HP K460 clustered servers are being used by the FBI as part of its Integrated Automated Fingerprint Identification System (IAFIS), which aims to allow the electronic submission of fingerprint data by police forces, with the results returned to law enforcement officers within two hours.
One group of about 135 FBI employees focuses on "latent print examination," which involves fingerprints found at a crime scene, not those taken directly from a hand. If an automated search against the master optical database cannot find an exact match to the submitted fingerprints, the automated search nevertheless may retrieve 20 sets of prints that are "close" to the set in question and download them to K460 servers.
The advantage of AutoRAID is that "it doesn't mean you have to automatically double your storage requirement if you want reliable data," said Pat Boyle, the deputy project manager for Integrated Tasking and Networking at Litton/PRC Inc., which is handling the ITN component of IAFIS.
Optical Gets Up to Speed
While disks seem likely to be the medium of choice for workgroup storage, optical is envisioned as the medium to accommodate future needs. Optical currently is used to store data that may be frequently accessed but that does not change often.
Optical is a good solution when "you still want access, but you're willing to accept slower recovery time," Labor's Brunner said. Instead of several milli-seconds, optical might take a second to retrieve a file.
Vendors of optical products have made an effort to improve access times. Procom Technology Inc., for example, recently released a new version of its entry-level networked CD-ROM server; this version combines CD-ROM and hard disk drives.Called DataForce 200, the system provides access to up to 20 CD-ROMS by mirroring their data on 18G of hard disks, which it treats as high-speed cache.
For the new product, the company claims speeds of up to 53X, which roughly translates to an 11-millisecond seek time, or about 7.95 megabytes/sec, said Bruce Matthews, the federal sales manager for Procom, Beltsville, Md. Access time for other CD technology can be at the much slower 32X, which is a 90-millisecond seek time, he said.
Capable of handling up to 100 users, the product sells for $5,300 to government users, Matthews said. And the product's CD Force software supports multiple platforms, so users running Microsoft Corp.'s Windows NT, Windows 95, Unix or IBM Corp.'s OS/2 can share a single storage system.
Among the users of the original product are the Air Force, the Navy, the Internal Revenue Service and some Department of Veterans Affairs facilities, Matthews said.
The Navy's Supervisor of Shipbuilding, Bath, Maine, uses a Procom 28-CD networked server system for accessing large parts databases, said Greg Desgrsseilliers, a network architect at the site. With a seven-bay CD tower that the shipbuilding office had tried out earlier, "you could only see the data from Novell [Inc.]," he said; the new product is more operating system-independent.
Optical is usually employed in environments where data does not change much. IBM Global Government Systems, for example, offers optical in "specific environments" such as storing data that may be needed for Freedom of Information Act requests, said Martin O'Dea, an IBM midrange storage specialist in Bethesda.Tape Finds a Place
With even slower access time than optical drives, tape drives generally have not had much of a role as workgroup storage solutions; instead, they have been used primarily as backup technology. However, some observers see that role changing.
Current tape technology, such as the IBM 3570 MagStar MP, provides data access at speeds "approaching optical drives," so users can get quick access to archives, O'Dea said.
The IBM 3570 tape subsystem delivers sustained data transfer performance of 6.6 megabytes/sec, the company said. The widely used digital linear tape technology, by contrast, retrieves data at approximately 5 megabytes/sec, he said.Typically, workgroups use tape for backup and recovery, O'Dea explained. "From there, it's a small step to get software" that performs hierarchical storage management as well as backup. HSM migrates less frequently used data to less-expensive storage media.
"The very low-end [workgroup storage users] can do it all with disk drives," he said. But sooner or later, "you reach a point where it's much more cost-effective to use tape than to continue to buy more disk" because it is a lot less expensive to store to tape than to disk.
HSM, which typically is associated with high-end storage solutions, is becoming more popular at the workgroup level, and it is extending from magnetic storage to cover optical and tape technology as well, Doculabs' Joshi said.
Microsoft, for example, is working to incorporate HSM capabilities into Windows NT 5.0, Joshi said. And other vendors are developing "NT-level HSM capabilities" that will start to emerge in the coming months.Role of Management Software
Storage management software in general is growing more important, although many low-end users do not understand the concept, Joshi said.
For example, EMASS Inc., Englewood, Colo., this month will begin shipping a Windows NT version of its AMASS software. With AMASS, a small workgroup might start with a small optical jukebox off a Windows NT server and offload less frequently accessed data onto a tape library with 50 to 100 pieces of tape, said John Pare, the area sales manager in Vienna, Va.
The advantage of the AMASS software is that it makes this collection of media "look like one big disk to the users in the workgroup."
Another storage management product is IBM's Adstar Distributed Storage Manager, which performs HSM as well as backup, restoration and archiving. An ADSM server, available on Windows NT as well as Unix, can move data to disk, tape or optical devices. ADSM supports more than 30 client types and is available on the General Services Administration schedule.
One ADSM user, the Energy Department's Pacific Northwest National Laboratory, employs the software to back up and restore home directories for approximately 150 users to tape, said Michael Valley, the lead system administrator at the facility. The lab is evaluating using the software's HSM features as well, Valley said, so that end users can set the parameters for off-loading files to less expensive storage.
-- Adams is a free-lance writer based in Alexandria, Va.
At A Glance
Status: Magnetic disks remain the preferred medium, but optical and tape drive vendors are making a pitch with their own workgroup storage solutions.
Issues: Vendors have improved access times and feature sets of optical and tape drive technology, potentially carving out workgroup storage niches.
Outlook: Good. Although the majority of users will stick with disks, agencies that need more complex solutions, such as HSM, have good options from which to choose.
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