OS Coexistence: The New World Order
By Peggy King
Unix and NT Server Market
Interoperability Between Unix and NT
Suppliers of Windows NT and Unix systems may believe they're locked in a
battle for the hearts and minds of customers, but many of those buyers plan
to use them both.
Microsoft's goal is to reach the top of the enterprise, and
its efforts to do so will focus the attention of everyone, friend or foe.
The operating system wars of the early 1990s have cooled off. An unofficial
truce accepts that Microsoft Windows dominates corporate desktops. Still
to be decided in some quarters is the role of Microsoft Windows NT as a
server OS. Corporate data center customers are beginning to use NT servers
as alternatives to Novell NetWare LANs for file and print services. And
despite scalability problems that still limit the processing load NT servers
can handle, some corporations are considering NT as an alternative platform
to Unix for applications moved from legacy systems to client/server environments.
Having enjoyed much success as mainframe alternatives in new enterprise
architectures, the leading Unix vendors are not eager to provide integration
between NT servers and their own more powerful--and more expensive--server
solutions. Only Digital Equipment Corp., whose Digital Unix ranks behind
HP-UX, IBM AIX and SunSoft Solaris in volume sales, has welcomed NT into
its operating system fold, offering both on its Alpha reduced instruction
set computing (RISC) processors. "Unlike the other major Unix vendors,
Digital sees Windows NT as an opportunity rather than a threat," says
Michael Goulde, a senior consultant at the Patricia Seybold Group of Boston.
User companies are running both Unix and NT servers for a variety of reasons.
Some are using NT to link up their substantial Windows presence. Others
wait to see whether NT will acquire the scalability and the applications
that they require in order to deploy it as an enterprise platform. Still
others prefer to have the two server operating systems coexist, each doing
what it does best. In general, Unix shines in the areas of networking, communications
among heterogeneous systems and processing-intensive applications. Windows
NT brings to the server qualities derived from Microsoft's success on the
Over the past two years, industry analysts, independent software vendors
(ISVs) and technologists in user organizations have examined the relative
strengths and weaknesses of each OS. Goulde sees similarities between Unix
and NT and some differences. "The two technologies are comparable in
many key areas: 32-bit support, multitasking, multithreading, security,
integrated networking and support for symmetric multiprocessing," he
says. "The advantages of Unix lie in its maturity, standards support,
distributed networking and scalability. NT's advantages are its ease of
installation, richness of graphical administration and support for a large
number of Windows applications."
Jerry Popek, chief technology officer for Platinum Technologies of Oakbrook
Terrace, IL, adds that Unix offers better support for database applications,
high-availability systems and asynchronous transfer mode (ATM) networking,
while NT offers better compatibility with the Win32 application programming
interface (an API specification published by Microsoft) and better support
for Microsoft's own networking protocols.
Running applications on both platforms is not the only way to integrate
them. Additional scenarios for the coexistence and/or integration of Unix
and NT include using one for application development and the other as the
deployment platform; deploying the "native" networking architecture
of one OS on the other; using both platforms as file and print servers;
sharing database applications in a three-tier client/server environment;
and using messaging middleware to provide a basic set of services for all
users. A look at some of the diverse issues surrounding Unix and NT coexistence
may suggest inklings for the future regarding integration between the two.
Bridging the Development Divide
Younger application developers often gain experience developing on PCs,
using tools such as Microsoft Visual Basic and PowerBuilder from Powersoft
of Burlington, MA, a division of Sybase. But in many large organizations
Unix remains the platform of choice for application development, especially
for those with enterprise-wide scope, because of its abundance of fourth-generation
languages and emerging object-oriented tools. As these once divergent development
styles and platforms meet in today's corporations, cross-platform porting
tools can help developers who prefer to work in Unix (even if the applications
are deployed on a Microsoft OS), as well as those who would rather develop
Unix applications using PC-based tools.
Some companies have decided to switch existing applications to NT in order
to migrate internally developed applications to less expensive server platforms;
nevertheless, they may want to retain their Unix development environment.
A company that decides to deploy Unix-based applications on NT has a few
options for doing so. It can retrain its developers to write to Win32 APIs,
hire new developers or port the applications. Tools such as NuTcracker from
DataFocus of Fairfax, VA, and Portage from Consensys Computers of Markham,
Ontario, Canada, enable developers working in Unix to port their software
to NT without having to rewrite it to Win32. To date, most of the customers
for these tools are ISVs who want to port their products, rather than users.
Both NuTcracker and Portage implement Unix APIs, including the system calls,
on NT. NuTcracker includes utilities provided as part of the MKS Toolkit
for NT from Mortice Kern Systems of Waterloo, Ontario. On the other hand,
NT-based products, including EXceed/NT from Hummingbird Software of Markham,
Ontario, and eXcursion for Windows NT from Digital Equipment, integrate
NT and X-based hosts by providing access to X Window System clients.
Tom Bosanko, president of Data Focus, argues that most development organizations
will retain their Unix orientation. "We don't have a single customer
that is replacing Unix with NT. Most of our customers are looking for compatibility
between the operating systems," he says. "Widespread acceptance
of Unix APIs helps protect investments in Unix training. Interoperability,
not replacement, occurs when NT is added to an existing environment."
Conversely, some developers skilled in working on PCs have to meet their
organizations' demand for Unix as the OS base. For example, application
developers at Lehman Brothers, a Wall Street financial services provider,
use Pentium-based PCs running Windows to create Unix server applications.
The firm has chosen Delphi from Borland International of Scotts Valley,
CA, because of its facility in reuse and rapid application development (RAD),
according to Jeffry Borror, managing director for Lehman Brothers in New
York. "Applications developed in Delphi are fluid and malleable yet
secure," he says. "They allow reuse down to the component level.
Unix has better networking, but when it comes to RAD the best tools are
now on the PCs."
Despite demand for NT-to-Unix porting and migration tools, Microsoft sets
limits on the support it offers to companies that want to use NT as a platform
for developing Unix applications. It allows source code access only to companies
selected to be part of its Windows Interface Source Environment (WISE) program.
Two WISE participants, Bristol Technologies of Ridgefield, CT, and Mainsoft
of Sunnyvale, CA, sell NT-based development environments that allow an application
written in conformance with Win32 to be ported to various Unix platforms.
Again, to date the vast majority of customers for these porting tools have
been ISVs and development teams within Unix system vendor organizations.
Networking Across Three Tiers
Perhaps the most typical environment in which OS coexistence is required
today is a three-tier client/server architecture. For many companies that
have reengineered their IT to support distributed computing, this includes
a back-end server, typically running Unix; a mid-level server for file and
print services that uses Unix, Windows NT or a network operating system
(NOS) such as NetWare; and PC clients running a Microsoft desktop OS. In
environments such as these, the network operating system architecture provides
the glue that integrates the diverse environments. Novell's decision not
to bring out "SuperNOS" versions of NetWare for Unix environments
removed one of the choices for users who wanted a NOS that would support
both Unix and PC environments.
Tim Yeaton, a director in Digital's Unix business segment in Nashua, NH,
describes two types of environments in which users have reason to use both
Unix and NT. In "Unix-centric" environments, PC servers running
NT often replace not the underlying Unix networking but NetWare in workgroup
and departmental servers. Connectivity to Unix enterprise servers and, increasingly,
to the Internet are key concerns. Support for TCP/IP and network file systems,
including NFS and AFS, are standards-based choices for providing integration
in environments that have Unix-based enterprise servers.
Microsoft has provided a 32-bit TCP/IP protocol stack in NT, but it leaves
support of NFS and AFS clients and servers to others. Third-party versions
of NFS for NT include BW-Connect NFS Server for Windows NT, from the Beame
and Whiteside subsidiary of Hummingbird Communications, and Chameleon 32NFS
from NetManage of Cupertino, CA. MultiNet for Windows version 1.2, a TCP/IP
product from TGV, Inc., of Santa Cruz, CA, includes NFS client support and
support for FTP clients and servers. Support for AFS on NT is available
as part of PC-Interface version 5.0 from the Locus Computing division of
Microsoft may have been responding to the wish lists of enterprise customers
by including in release 3.5 of NT support for the Microsoft-developed Dynamic
Host Configuration Protocol (DHCP) for TCP/IP. Using DHCP, system managers
avoid the error-prone process of assigning IP addresses manually. At the
New Mexico Department of Public Safety (DPS) in Santa Fe, which has Digital
2100 Alpha servers running both Unix and NT under TCP/IP, technical director
Larry White recalls having a major problem when a technician inadvertently
confused client and server IP addresses before support for DHCP was available.
"Dynamic assignment of IP addresses is a real advantage. The DHCP database
included in the server version of NT 3.5 allows us to keep track of our
remote users who log in on notebook computers," says White.
Despite this advance, NT sites with enterprise networking still have lengthy
wish lists. Bob Riddle, manager of client/server technology at the University
of Michigan's Center for the Integration of Information Technology (CIIT)
in Ann Arbor, hopes that built-in support for AFS, which is rumored to be
under development at Microsoft, will be part of the next release of the
NT server version.
For "Microsoft-centric" organizations that nevertheless have Unix
servers, a product such as Advanced Server for Unix (AS/U), an enhanced
version of LAN Manager for Unix from the Software and Communications Solutions
Group of AT&T GIS in Lincroft, NJ, helps. AS/U is a Unix-based NOS that
integrates PC systems running Microsoft Windows desktops and provides Windows
users with full NT server networking, including trusted domains and network
security. AT&T GIS licenses AS/U and resells it on an OEM basis to other
Unix vendors, among them Data General, Groupe Bull, Pyramid Technology,
the Santa Cruz Operation (SCO) and Unisys. HP and DEC, whose version of
the product will be called Pathworks version 6 for Digital Unix, plan to
release their versions early this year.
State Fund Mutual Insurance in Minneapolis had been a user of LAN Manager
for Unix on the SCO platform before the company began to rearchitect its
computing environment. The new architecture will have a DG Aviion 9500 running
an Oracle database as the enterprise server. In the middle tier, a Compaq
Proliant 1000 will run key applications, including the company's fax software
and an electronic data interchange (EDI) application, on SCO OpenServer
The company is in the process of migrating its desktop clients from Windows
3.1 to Windows 95. During the migration to Windows 95, system administrator
Bill Slott discovered that the graphical network administration tools he
had been able to use under LAN Manager for Unix no longer worked. Rather
than switch to Unix-style networking, State Fund Mutual became an early
customer for Advanced File and Print server, the SCO version of AS/U. At
present, State Fund Mutual's only need for NT is on the client side, as
a network management console to use the graphical administration tools.
By moving to Advanced File and Print Server, Slott and his team are prepared
to implement NT as a second middle-tier server if the company needs PC applications
not available on the SCO platform.
Another way to integrate Unix and NT is through cross-platform implementations
of the Open Software Foundation's Distributed Computing Environment (DCE).
It offers a means of establishing uniform services for users without regard
to which operating system they have. "We're not in a position to dictate
what platform our customers use," says Bob Riddle of the University
of Michigan's CIIT. One of its goals is to provide each user with a set
of services including directory lookup, Kerberos security, mail, news, conferencing
and file services. The university has Unix workstations, Windows PCs and
about 20,000 Macintosh desktops. "For us, DCE is another level of abstraction
upon which to build services," says Riddle. "By building on APIs,
we can, for instance, build our e-mail on Unix one year and switch to NT
the next." CIIT used PC-DCE32 for Windows NT from Gradient Technologies
of Marlboro, MA.
NoT Yet for the Database
Moving up the tiers of client/server, one finds little of NT now. For example,
it has not penetrated the enterprise-level database server, for both marketing
and technical reasons. Lack of scalability is a key issue on the technical
side. "Until support for symmetric multiprocessing systems with more
than four processors matures, there's a ceiling to the scalability of NT,"
says Goulde of the Seybold Group. "Unlike high-end Unix servers, NT
servers can't support terabyte databases, which require at least 256MB of
memory to provide adequate performance."
Vendors of relational database management systems (RDBMS) whose main platforms
run Unix seem to be in no rush to support NT at the enterprise level. Their
reasons range from the technical effort required to the business fact that
PC-based products traditionally sell for less than Unix ones. By limiting
support for NT to the workgroup level, the vendors can avoid, at least temporarily,
the price erosion that usually accompanies a port to a Microsoft operating
system. All of the major Unix RDBMS vendors have products available on the
NT server platform, but these tend to be workgroup implementations that
lack industrial-strength features such as replication and support for multiprocessing
found in the Unix-based enterprise versions.
When vendors deliver full-featured versions of their flagship RDBMS products,
some customers will be ready to buy. The New Mexico DPS has designed its
integrated criminal justice system with the goal of being able to move its
Oracle database applications to NT. Because its Unix database is implemented
on a 64-bit Digital Alpha server that can also run NT, this anticipated
change of OS will occur without change of hardware. According to Larry White,
the department decided to cluster its Alpha servers to achieve fail-over
capabilities. "It costs us only a bit more to get fault tolerance for
our mission-critical applications," he says.
The department is willing to be a beta site for NT clustering that would
make it possible to cluster Alpha RISC servers with smaller Intel Pentium-based
servers. Digital is working with Microsoft to deliver this type of multiplatform
clustering. "Clustering different types of NT servers would give us
both high availability and load balancing," says White. But having
such a solution for the department's enterprise database depends upon Oracle
delivering a version that supports the clustering.
Enterprise Platform Prospects
In the current state of the art, the high end of distributed computing belongs
to some repositioned legacy systems and to Unix servers. Microsoft's goal
is to reach the top of the enterprise, and its efforts to do so will focus
the attention of everyone, friend or foe. "Microsoft is building its
capabilities as an enterprise supplier, but it has quite a distance to go,"
says Goulde. "It will take several years of tuning and optimizing before
NT will scale up well on 16-, 24-, and 32-processor systems. How fast this
will happen depends to a large extent on how much of a priority it is for
Stock brokerage Cowan and Co. of New York is moving third-party applications
to NT as they become available. For example, the company has decided to
move Lotus Notes from OS/2 servers to NT when Lotus brings out the full
32-bit NT version that was announced before IBM acquired Lotus. "We
still use applications that run only on Unix, but we encourage our vendors
to provide them under NT," says CIO Armand Keim. "As a midsize
company, we have to be pragmatic about moving to NT, because we aren't big
enough to do the migration work ourselves."
Keim can envision using NT at the enterprise level if it were possible for
Cowan to replace its mainframe with servers running NT applications. Until
NT servers can scale beyond four symmetric multiprocessing CPUs, however,
he won't risk attempting an all-NT environment on the enterprise level.
Whether NT servers will become capable enterprise servers, and whether they
will replace Unix systems in doing so, are among the most pressing questions
in the IT industry. Some midsize companies will find the applications they
need, but to use them may mean having to manage a complex network configuration
with numerous single-application PC servers. Enterprise-quality applications
from major ISVs, including CA-UniCenter from Computer Associates of Islandia,
NY; R/3 from SAP America of Philadelphia; and the Tivoli Management Environment
from Tivoli Systems of Austin, TX, are scheduled to debut on NT servers.
Whether those versions will match the functionality of their Unix equivalents
remains to be determined. It will be more than interesting to see what servers
reside in corporate data centers a few years from now.
Peggy King is a free-lance writer based in San Jose, CA,
who specializes in the business aspects of open systems. She can be reached