Linux vs' Windows NT

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Linux vs. Windows NT

• Rehana Shrestha

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Linux vs. Windows NT

• History
• Design Principles
• System Components
• Kernel
• Memory Management
• File Systems
• Security
• Networking

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History of Linux

• 1991 self-contained kernel for 80386 processor,
  the first true 32-bit processor in Intels range
  of PC-compatible CPUs
• Development revolved largely around the central
  operating-system kernel - that manages all system
  resources and that interacts directly with the
  hardware
• The Kernel is an entirely original piece of
  software developed from scratch by the Linux
  community
• The Linux system includes a multitude of
  components, some written from scratch, others
  borrowed from other development projects or
  created in collaboration with other teams
• Linux distribution includes all the standard
  components of the Linux system, a set of
  administrative tools to simplify the initial
  installation and upgrading of Linux, and to
  manage installation and de-installation of other
  packages on the system

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History of Windows NT

• 1988 by Microsoft portable operating system that
  supported both the OS/2 and POSIX application
  programming interfaces (APIs).
• NT was supposed to use the OS/2 API as its native
  environment, but during the development NT was
  changed to use the 32-bit Windows API for Win32
  API, reflecting the popularity of Windows 3.0
• The first Version of NT were Windows NT 3.1 and
  Windows NT 3.1 Advanced Server.
• In Version 4.0, NT adopted the Windows 95 user
  interface and incorporated Internet web-server
  and browser software

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Design Principles of Linux

• Multi-user, multitasking system with a full set
  of UNIX-compatible tools
• runs on a wide variety of platforms, in its early
  days it was developed exclusively on PC
  architecture, run on a multiprocessor machine
  with hundreds of megabytes of main memory and
  many gigabytes of disk space, but it is still
  capable of operating under 4 MB of RAM
• Speed and efficiency are important design goals,
  but much of the recent and current work has
  concentrated on Standardization.
• Supporting a wide base of applications is
  important for any operating system, so
  implementation of standards is a major goal for
  Linux development even if the implementation is
  not formally certified. There is a substantial
  expense involved in certifying an operating
  systems compliance with most standards.

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Design Principles of NT

• Extensibility, portability, reliability,
  compatibility, performance, and international
  support
• Extensibility hopes to keep up with advancement
  in computing technology
• NT uses loaded drivers in the I/O system, so that
  new file systems, new kinds of I/O devices, and
  new kinds of networking can be added while the
  system is running
• NT utilizes a client-server model like the Mac
  operating system, and supports distributed
  processing by remote procedure calls
• Portable it can be moved from one hardware
  architecture to another with relatively few
  changes.

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Design Principles of NT

• Reliability ability to handle error conditions,
  including the ability of the operating system to
  protect itself and its users from defective or
  malicious software.
• NT comes with a file system, called the native NT
  file system (NTFS), that recovers automatically
  from many kinds of file system errors after a
  system crash.
• Compatibility NT can run the executable binaries
  for many programs compiled for Intel X86 running
  MS-DOS, 32-bit Windows, OS/2, LAN Manager, and
  32-bit Windows.
• Performance communicate with one another
  efficiently by a local-procedure-call facility
  that provides high-performance message passing
• International use support for different locales
  via the national language support API.

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System Components of Linux

• Kernel responsible for maintaining all the
  important abstractions of the operating system,
  including such things as virtual memory and
  processes
• System libraries a standard set of functions
  through which applications can interact with the
  kernel, and which implement much of the operating
  system functionality that does not need the full
  privileges of kernel code
• System utilities programs that perform
  individual, specialized management tasks.
•  

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System Components of NT

• The architecture of NT is a layered system of
  modules.
• The main layers are the hardware, abstraction
  layer, the kernel and the executive that run in
  protected mode, and a large collection of
  subsystems that run in user mode.

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Kernel of Linux

• First Linux kernel was version 0.01, dated May
  14th 1991.
• It has no networking, ran on only 80386
  compatible Intel processors and PC hardware, and
  had extremely limited device-driver support
• In March 14, 1994 Linux 1.0 was released. This
  included support for UNIXs standard TCP/IP
  networking protocols as well as a BSD compatible
  socket interface for networking programming.
  Device-driver support was added for running IP
  over an Ethernet or over serial lines or modems.

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Kernel of Linux Cont..

• In March 1995, the 1.2 kernel was released. It
  include support for a much wider variety of
  hardware, including PCI hardware bus
  architecture, support for 80386 CPUs virtual
  8086 mode, networking stack was updated to
  provide support for the IPX protocol, and a more
  complete IP implementation was provided that
  included accounting and firewall functionality
• Linux 2.0 was released in June 1996. This include
  support for multiple architectures, including a
  fully 64-bit native Alpha port, and support for
  multiprocessor architectures. Linux distributions
  based on 2.0 are also available for the Motorola
  68000-series processors and for Suns Sparc
  systems. It also included much improved TCP/IP
  performance, and a number of new networking and
  ISDN support.

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Kernel of Windows NT

• The kernel of NT provides the foundation for the
  executive and the subsystems. It has four main
  responsibilities thread scheduling, interrupt
  and exception handling, low-level processor
  synchronization, and recovery after a power
  failure.
• The kernel is object-oriented. An object type in
  NT is a system-defined data type that has a set
  of attributes and a set of methods. The kernel
  uses two sets of objects. The first set of
  objects is the dispatcher objects. These control
  dispatching and synchronization in the system.
  The second set of kernel objects comprises the
  control objects. These objects include
  asynchronous procedure calls, interrupts, power
  notify, power status, process, and profile
  objects

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Memory Management of Linux

• Two components to memory management
• First Physical memory-management system deals
  with allocating and freeing pages, groups of
  pages, and small blocks of memory.
• Second Handles virtual memory, which is memory
  mapped into the address space of running
  processes.

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Memory Management of NT

• The Win32 API provides several ways for an
  application to use memory virtual memory,
  memory-mapped files, heaps, and thread-local
  storages.
• One way to use memory is by memory mapping a file
  into its address space. Memory mapping is also a
  convenient way for two processes to share memory
  both processes map the same file into their
  virtual memory. Memory mapping is a multistage
  process

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File Systems of Linux

• Linux kernel handles various different types of
  file by hiding the implementation details of any
  single file type behind a layer of software, the
  virtual file system (VFS)

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File Systems of Windows NT

• Historically, MS-DOS systems have used the
  file-allocation table (FAT) file system. The
  16-bit FAT file system has several shortcomings,
  including internal fragmentation, a size
  limitation of 2 GB, and a lack of access
  protection for files. The 32-bit FAT file system
  has solved the size and fragmentation problems,
  but the performance and features are still weak
  by comparison with modern file systems. The NTFS
  is much better. It was designed with many
  features in mind, including data recovery,
  security, fault tolerance, large files and file
  systems, multiple data streams, UNICODE names,
  and file compression.

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Security of Linux

• Its security model can be classified in two
  groups
• Authentication Making sure that nobody can
  access the system without first providing that
  she has entry rights
• Access control Providing a mechanism for
  checking whether a user has the right to access a
  certain object, and preventing access to objects
  as required

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Security of Windows NT

• Security of an NTFS volume is derived from the NT
  object model. Each file object has a security
  descriptor attribute stored in its MFT record.
  This attribute contains the access token of the
  owner of the file, and an access-control list
  that states the access privileges that are
  granted to each user that has access to the file.

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Networking in Linux

• supports number of protocols native to other,
  non-UNIX operating systems such as Apple-Talk and
  IPX.
• The important set of protocols in the Linux
  networking system is the Internet Protocol (IP)
  suite. This suite comprises a number of separate
  protocols. The IP implements routing between
  different hosts anywhere on the network. On top
  of the routing protocol are built the UDP, TCP,
  and ICMP protocols. The UDP protocol carries
  arbitrary individual datagrams between hosts,
  whereas TCP implements reliable connections
  between hosts with guaranteed in-order delivery
  of packets and automatic retransmission of lost
  data. ICMP is used to carry various error and
  status messages between hosts.
• Internally, networking in the Linux kernel is
  implemented by three layers of software
• The socket interface
• Protocol drivers
• Network device drivers

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Networking in Windows NT

• NT supports both peer-to-peer and client-server
  networking
• The networking components in NT provide data
  transport, inter-process communication, file
  sharing across a network, and the ability to send
  print jobs to remote printers.
• NT comes with several networking protocols
• Server message-block protocol is used to send I/O
  requests over the network.
• Network Basic Input/Output System (NetBIOS) is a
  hardware-abstraction interface for networks,
  which is used to establish logical names on the
  network, to establish logical connections or
  sessions between two logical names on the
  network, and to support reliable data transfer
  for a session via either NetBIOS or SMB requests

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Networking in Windows NT

• The NetBIOS Extended User Interface (NetBEUI) was
  introduced by IBM in 1985 as a simple, efficient
  networking protocol for up to 254 machines. It is
  the default protocol for Windows 95 peer
  networking and for Windows for Workgroups.
• The point-to-point tunneling protocol (PPTP) is a
  new protocol provided by Windows NT 4.0 to
  communicate between remote-access server modules
  running on NT machines that are connected over
  the Internet.
• The data-link control (DLC) protocol is used to
  access IBM mainframes and HP printer that are
  connected directly to the network.
• The AppleTalk protocol was designed as a low-cost
  connection by Apple so that Macintosh computers
  could share files. NT systems can share files and
  printers with Macintosh computers via AppleTalk
  if an NT server on the network is running the
  Windows NT Services for Macintosh package.

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References

• www.whatis.com
• www.ask.com
• Operating System Concepts, Fifth Edition