With all the recent attention around Linux as an operating system, it's important to step back from the hype and look at the reality. First, it's worth noting that Linux is a UNIX-like operating system. Linux fundamentally relies on 30-year-old operating system technology and architecture. Linux was not designed from the ground-up to support symmetrical multiprocessing (SMP), graphical user interfaces (GUI), asynchronous I/O, fine-grained security model, and many other important characteristics of a modern operating system. These architectural limitations mean that as customers look for a platform to cost effectively deploy scalable, secure, and robust applications, Linux simply cannot deliver on the hype.
Myth: Linux performs better than Windows NT
Reality: Windows NT 4.0 Outperforms Linux On Common Customer Workloads
The Linux community claims to have improved performance and scalability in the latest versions of the Linux Kernel (2.2), however it's clear that Linux remains inferior to the Windows NT® 4.0 operating system.
|For File and Print services, according to independent tests conducted by PC
Week Labs, the Windows NT 4.0 operating system delivers 52 percent
better performance on a single processor system and 110 percent better
performance on a 4-way system than similarly configured single processor and
4-way Linux/SAMBA systems.
||For Web servers, the same PC Week tests showed Windows NT 4.0 with
Internet Information Server 4.0 delivers 41 percent better performance on a
single processor system and 125 percent better performance on a 4-way system
than Linux and Apache.
||For e-commerce workloads using secure sockets (SSL), recent
PC Magazine tests showed Windows NT 4.0 with Internet Information Server
4.0 delivers approximately five times the performance provided by Linux and
||For transaction-orientated Line of Business applications, Windows NT 4.0
has achieved a result of 40,368 tpmC at a cost of $18.46 per transaction on
a Compaq 8-Way Pentium III XEON processor-based system. This industry
leading price/performance result from the Transaction
Processing Performance Council (TPC) clearly shows how Windows NT can
deliver world-class performance for heavy duty transaction processing. It's
interesting to note that there is not a single TPC result on any database
running on Linux, and therefore Linux has yet to demonstrate their
capabilities as a database server.
||Linux performance and scalability is architecturally limited in the 2.2
Kernel. Linux only supports 2 gigabytes (GB) of RAM on the x86 architecture,1
compared to 4 GB for Windows NT 4.0. The largest file size Linux supports is
2 GB versus 16 terabytes (TB) for Windows NT 4.0. The Linux SWAP file is
limited to 128 MB. In addition, Linux does not support many of the modern
operating system features that Windows NT 4.0 has pioneered such as
asynchronous I/O, completion ports, and fine-grained kernel locks. These
architecture constraints limit the ability of Linux to scale well past two
||The Linux community continues to promise major SMP and performance
improvements. They have been promising these since the development of the
2.0 Kernel in 1996. Delivering a scalable system is a complex task and it's
not clear that the Linux community can solve these issues easily or quickly.
As D. H. Brown Associates noted in a recent technical report,2
the Linux 2.2 Kernel remains in the early stages of providing a tuned SMP
Myth: Linux is more reliable than Windows NT
Reality: Linux Needs Real World Proof Points Rather than Anecdotal Stories
The Linux community likes to talk about Linux as a stable and reliable operating system, yet there are no real world data or metrics and very limited customer evidence to back up these claims.
|Windows NT 4.0 has been proven in demanding customer environments to be a
reliable operating system. Customers such as Barnes and Noble, The Boeing
Company, Chicago Stock Exchange, Dell Computer, Nasdaq and many others run
mission-critical applications on Windows NT 4.0.
||Linux lacks a commercial quality Journaling File System. This means that
in the event of a system failure (such as a power outage) data loss or
corruption is possible. In any event, the system must check the integrity of
the file system during system restart, a process that will likely consume an
extended amount of time, especially on large volumes and may require manual
intervention to reconstruct the file system.
||There are no commercially proven clustering technologies to provide High
Availability for Linux. The Linux community may point to numerous projects
and small companies that are aiming to deliver High Availability
functionality. D. H. Brown recently noted that these offerings remain
immature and largely unproven in the demanding business world.
||There are no OEMs that provide uptime guarantees for Linux, unlike Windows
NT where Compaq, Data General, Hewlett-Packard, IBM, and Unisys provide 99.9
percent system-level uptime guarantees for Windows NT-based servers.|
Myth: Linux is Free
Reality: Free Operating System Does Not Mean Low Total Cost of Ownership
The Linux community will talk about the free or low-cost nature of Linux. It's important to understand that licensing cost is only a small part of the overall decision-making process for customers.
|The cost of the operating system is only a small percentage of the overall
total cost of ownership (TCO). In general Windows NT has proven to have a
lower cost of ownership than UNIX. Previous studies have shown that Windows
NT has 37 percent lower TCO than UNIX. There is no reason to believe
that Linux is significantly different than other versions of UNIX when it
comes to TCO.
||The very definition of Linux as an Open Software effort means that
commercial companies like Red Hat will make money by charging for services.
Therefore, commercial support services for Linux will be fee-based and will
likely be priced at a premium. These costs have to be factored into the
total cost model.
||Linux is a UNIX-like operating system and is therefore complex to
configure and manage. Existing UNIX users may find the transition to Linux
easier but administrators for existing Windows®-based or Novell
environments will find it more difficult to handle the complexity of Linux.
This retraining will add significant costs to Linux deployments.
||Linux is a higher risk option than Windows NT. For example how many
certified engineers are there for Linux? How easy is it to find skilled
development and support people for Linux? Who performs end-to-end testing
for Linux-based solutions? These factors and more need to be taken into
account when choosing a platform for your business.
Reality: Linux Security Model Is Weak
All systems are vulnerable to security issues, however it's important to note that Linux uses the same security model as the original UNIX implementations--a model that was not designed from the ground up to be secure.
|Linux only provides access controls for files and directories. In contrast,
every object in Windows NT, from files to operating system data structures,
has an access control list and its use can be regulated as appropriate.
||Linux security is all-or-nothing. Administrators cannot delegate
administrative privileges: a user who needs any administrative capability
must be made a full administrator, which compromises best security
practices. In contrast, Windows NT allows an administrator to delegate
privileges at an exceptionally fine-grained level.
||Linux has not supported key security accreditation standards. Every member
of the Windows NT family since Windows NT 3.5 has been evaluated at either a
C2 level under the U.S. Government's evaluation process or at a
C2-equivalent level under the British Government's ITSEC process. In
contrast, no Linux products are listed on the U.S. Government's evaluated
||Linux system administrators must spend huge amounts of time understanding
the latest Linux bugs and determining what to do about them. This is made
complex due to the fact that there isn't a central location for security
issues to be reported and fixed. In contrast Microsoft provides a
single security repository for notification and fixes of security related
||Configuring Linux security requires an administrator to be an expert in
the intricacies of the operating system and how components interact.
Misconfigure any part of the operating system and the system could be
vulnerable to attack. Windows NT security is easy to set up and administer
with tools such as the Security Configuration Editor.|
Myth: Linux can replace Windows on the desktop
Reality: Linux Makes No Sense at the Desktop
Linux as a desktop operating system makes no sense. A user would end up with a system that has fewer applications, is more complex to use and manage, and is less intuitive.
|Linux does not provide support for the broad range of hardware in use
today; Windows NT 4.0 currently supports over 39,000 systems and devices on
the Hardware Compatibility List. Linux does not support important
ease-of-use technologies such as Plug and Play, USB, and Power Management
||The complexity of the Linux operating system and cumbersome nature of the
existing GUIs would make retraining end-users a huge undertaking and would
add significant cost
||Linux application support is very limited, meaning that customers end up
having to build their own horizontal and vertical applications. A recent
report from Forrester Research highlighted the fact that today 93 percent of
enterprise ISVs develop applications for Windows NT, while only 13 percent
develop for Linux.3|
2. Linux: How Good Is It? D. H. Brown Associates Inc. April 1999
3. Forrester Research, Software Vendors Crown Server OS Kings, Aug. 31, 1999