Serving up an operating system

Overall costs and integration with legacy systems are the top concerns when government buyers pick server operating systems. This leads to several distinct choices: Unix Novell Corp.'s popular NetWare package or up-and-comer Windows NT from Microsoft Corp.

"Cost ease of implementation and software availability are the predominant factors when choosing server operating systems with performance and scalability as close secondary concerns " said Scott Winkler vice president of platforms and operating systems at The Gartner Group Stamford Conn.Federal buyers prefer Unix for heavy processing needs while NT does better in environments with lighter processing needs and application-oriented servers. With its emphasis on file and print performance NetWare remains the favorite for the largest federal networks. While still the dominant network operating system in the federal government however NetWare is seen as a diminishing presence.

Market analyst International Data Corp. found recently that NT had stepped up from 17 percent penetration of federal sites in January 1995 to 30 percent by July 1996. During the same period the use of NetWare declined from 48 percent to 45 percent.

"The trend we see is Unix holding its position NetWare share eroding slowing and NT usage growing rapidly " said Steve LeCompte vice president of IDC Government Market Services Falls Church Va.Gartner's Winkler also saw a slight decline in the use of NetWare in sites with fewer than 500 users these sites are moving rapidly to NT. But he pointed out in sites that go as high as 5 000 users the trend is to stick with NetWare.

While Winkler and other analysts predict that the use of NT will continue to accelerate and may even surpass Unix in the number of site installations they stop short of saying that NT will obliterate Unix."Total Unix is growing at a slower rate than NT because it's a mature well-established market. NT is new so it's experiencing the rapid growth of a new market " pointed out Jean Bozman an IDC server analyst Mountain View Calif.

Users tend to agree.

"Our bids have tended to come in more with the NT solution in the last year or two " said Kevin Carroll director of the Army Information System Selection and Acquisition Agency Alexandria Va. "But there will always be a need for Unix for the large number of installed applications we already have running in Unix."The existing Unix server environments are stable and I don't foresee switching to NT in the strategic higher- end environments " he said.

Unix Remains Strong

Unix has held or expanded its presence on a number of fronts such as in IBM mainframe shops moving to client/server computing or in the growing use of the Internet. It has become the centerpiece of large number-crunching environments with Internet initiatives.

The Naval Surface Warfare Center Dahlgren Va. has one of the more demanding sets of requirements for a 32-bit server operating environment. The center is running a test bed of Unix operating environments in order to select a prototype for a surface-ship weapon system.

"There are a very small number of commercial operating systems that fulfill all of our requirements " said Eric LeGore a performance engineer at the center. "Our applications do a lot of calculations based on time. You have to be able to calculate intercept points where missiles and targets will meet."When we're talking time-critical we mean sub-hundred milliseconds to get something done across multiple platforms " he stressed.

The successful operating system must meet the largest number of the center's criteria as possible and the vendor must promise to provide in the future whatever needed functions are not in the current operating system release.

The center is testing four Unix operating environments: Sun Microsystems Inc.'s Solaris 2.5 on SPARC servers and on Sun's Ultra SPARC 64-bit servers Hewlett-Packard Co.'s HP/UX on HP 9000 servers Digital Equipment Corp.'s Unix on Digital Alpha64-bit machines and OSF RT (the Open Software Foundation's Real Time operating system) on HP 9000 and Pentium servers.

The center needs real-time scheduling control and pre-emption so that a higher-priority process can pre-empt a lower-priority process. The operating system also must contain the ability to wire down memory - that is to dedicate memory permanently to certain time-critical applications.

Instrumentation within the operating system is critical to the center because all system events must be recorded and time-stamped with speed and accuracy.

Another crucial criterion is the ability to have 10 percent flexibility in an operating system that is 90 percent symmetric multiprocessing-capable. The 10 percent should allow systems administrators to dedicate one or two priority processes a concept known as "processor sets" by Sun and OSF.

The final two criteria are capabilities LeGore said he hasn't yet seen completely implemented in any 32-bit operating environment. One is fault detection at three levels: for application processes the operating system itself and the CPU. The other is low latency deterministic communications which allows input/output to send information across the network consistently within a specified amount of time."If machines are CPU-loaded then time-critical messages could take hundreds of milliseconds " LeGore said.

"That's not acceptable in some cases. [Then] we need to guarantee that messages get from one application to another across the network in tens of milliseconds."

Although testing is not complete and no system has been chosen yet LeGore said Sun's Solaris looks promising. "It has what we need in the areas of scheduling control and instrumentation and it is strongly Posix-compliant " he said.

Unix also runs the show at the Library of Congress' National Digital Library Program an initiative to digitize 5 million items of historical American material and make it available to the public on the Internet.Six years ago Tom Littlejohn a senior systems programmer at the library wanted to update the library's IBM MVS mainframe system with Unix.

"I didn't have a lot of experience with Unix at the time so [IBM's] AIX on the RS/6000 was my first experience with it " he said. The library ended up standardizing on the RS/6000 running AIX one year ago.However many federal application environments do not require as rigorous processing as the Navy's weapons systems. For large office applications Windows NT is increasingly popular among government users especially where Microsoft applications already have been established.

"Windows NT was something we grew into and it integrated well with everything we'd previously done " said Bruce Harmon chief of information resources management at the Air Force Personnel Center Randolph Air Force Base Texas.

Harmon is using NT as the network operating system for the local-area network that connects 28 Compaq Computer Corp. 4500 and 5000 file servers at the center. The server links to Honeywell mainframes that contain records for every individual in the Air Force.

Already a Microsoft user the center began running the Microsoft BackOffice Suite of applications and evolved from LAN Manager to Windows NT three years ago.

"Microsoft's position in the market means [there's] a lot of third-party vendor support " Harmon said. "If we have a customer with a specific application need we normally do not have a problem finding a solution for them."

Harmon named ease of implementation maintenance and scalability as three other reasons he is content with Windows NT. In fact in his responsibility for office automation at the center Harmon's plans are pinned to expansion of and compatibility with NT.

"We're moving to expand the use of NT to a database server as well as a network and e-mail server " he said. "We require that the document storage and retrieval system works well with NT. We're looking seriously at Microsoft's Sequel 6.5 database now because it integrates well with NT."

Novell meanwhile is looking to the latest release of its operating system NetWare 4.11 to boost its appeal to federal users. Code-named Green River it is scheduled to ship this fall.

Novell is touting traditional NetWare strengths such as security along with new features such as built-in Internet and intranet support as reasons why users will continue to give close attention to the Novell product. Even in situations where NT is making inroads the feeling among many users is that NetWare and NT can coexist well.

Novell officials said despite the challenge from NT they have yet to suffer a significant loss in an agency where NetWare is dominant (see story page 90).

64-Bit Operating Systems

There are applications where a 32-bit operating system is not enough. To take advantage of advances in the sensitivity of electronic instruments scientists at NASA's Goddard Space Flight Center Greenbelt Md. need the increased speed and memory provided by Digital's 64-bit Unix operating system and Alpha 3000 Model 600 workstations.

"More sensitive instruments today allow us to take data faster so we have to process it faster " said Gary Hinshaw the principal scientist at Hughes STX Corp. which is providing technical support to Goddard for the Cosmic Background Explorer project. Cobe is mapping temperature differences in the sky to discover origins of the universe.

Hinshaw and other scientists take raw data collected by a satellite and write programs using Digital's Fortran 90 to do data reduction and processing on the 64-bit system. The customized applications are specific to the satellite.

"A lot of the measuring of temperature in the sky is done in the data proc-essing " Hinshaw said.Although Hinshaw noted that the scientific community has moved off Digital's VMS operating system and onto the company's Unix system the use of the high-end 64-bit systems is nascent in mainstream government or commercial concerns.

"We've seen little concern for 64-bit operating systems. It's the rare user who needs it yet. They may in the future but not now " Winkler said.

"Users should be aware of their vendors' strategies to move from 32- to 64-bit but programmers are not running into 32-bit limitations like they were with 16-bit programs " he added.v

Gerber is a free-lance writer based in Kingston N.Y.

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AT A GLANCE

Status: The overall market is relatively robust although major shifts are apparent with Microsoft NT quickly gaining ground.

Issues: Cost and ease of implementation are increasingly important considerations although integration with legacy systems remains a major concern.

Outlook: Mixed. While demand remains good the battle for market share leaves the technical picture cloudy.

The perfect server operating system

If he were designing the perfect server operating system the Naval Surface Warfare Center's Eric LeGore would include the following elements:* Scheduling control.* Instrumentation.* Fast system clock access and high resolution.* Posix compliance.* Predominantly symmetric multiprocessing capable.* Fault detection and recovery.* Low latency deterministic communications.