1. You have installed windows service pack 2 and after updating windows up to service pack 3, you are able to log in system but receiving a continuous message that it is not a genuine copy of windows. What are the solutions available to this problem in both manner legal of illegal?
Illegal
Windows Genuine Notification popped up because Windows Update again installed it via Automatic Updates. It pops up while a user logs in to windows, displays a message near the system tray and keeps on reminding you in between work that the copy of windows is not genuine. It has been reported since its first release that even genuine users are getting this prompt, so Microsoft has them self release instructions for its removal. When I searched on Google about this issue, I landed up on pages which were providing many methods of its removal including those patching up existing files with their cracked versions which I would highly recommend avoiding them as they might contain malicious code and can be used to get you into more trouble.
I found out this method of removal of Windows Genuine Notification :
1. Launch Windows Task Manager.
2. End wgatray.exe process in Task Manager.
3. Restart Windows XP in Safe Mode.
4. Delete WgaTray.exe from C:\Windows\System32.
5. Delete WgaTray.exe from C:\Windows\System32\dllcache.
6. Lauch RegEdit.
7. Browse to the following location: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\Notify
8. Delete the folder ‘WgaLogon’ and all its contents
9. Reboot Windows XP.
But the latest version of the WGN tool is a little tricky to handle. It will pop up again as soon as you end it from the task manager and while it is running in the memory, you can’t delete it too.
Illegal
Download a patch from the Internet and run it in your windows
Legal
Register your windows from Microsoft official website.
2.You have downloaded windows 7 from Microsoft official website in December 2009 on present day your system is rebooting after 2 hours. What are the solutions available to overcome this problem. Legal or Illegal?
Ans:
If you have a warm fuzzy feeling inside when thinking about Microsoft and their decision to let you play with their new OS for free until August next year; get ready for the kicker. From March that release candidate you are running is going to start reminding you a commercial copy of the OS needs to be purchased to continue enjoying the benefits of Windows 7 in the most intrusive way possible.
You can understand Microsoft wanting to remind users that they need to buy Windows 7, but it’s the method they have decided to employ that is going to annoy and frustrate users. From March 2010 Windows 7 RC will start automatically rebooting your PC every two hours. So, if you happen to be doing something important you’ll have to stop as the friendly “buy me!” shutdown reminder is invoked.
For the RC, bi-hourly shutdowns will begin on March 1st, 2010. You will be alerted to install a released version of Windows and your PC will shut down automatically every 2 hours. On June 1st, 2010 if you are still on the Windows 7 RC your license for the Windows 7 RC will expire and the non-genuine experience is triggered where your wallpaper is removed and “This copy of Windows is not genuine” will be displayed in the lower right corner above the taskbar.
This isn’t a new tactic Microsoft has implemented to remind users they need to upgrade and it did the same thing with Vista previews. Windows 7 is expected to release in October this year, but at the very latest will be out by January next year giving you plenty of time to buy a copy before the automatic shutdowns begin.
Friday, March 12, 2010
Wednesday, March 10, 2010
FAT VS NTFS. WHICH FILE SYSTEM IS TO BE CHOSEN
FAT16, FAT32 and NTFS each use different cluster sizes depending on the size of the volume, and each file system has a maximum number of clusters it can support. The smaller the cluster size, the more efficiently a disk stores information because unused space within a cluster cannot be used by other files; the more clusters supported, the larger the volumes or partitions that can be created.
The table below provides a comparison of volume and default cluster sizes for the different Windows file systems still commonly in use:
Which File System to Choose?
As much as everyone would like for there to be a stock answer to the selection question, there isn't. Different situations and needs will play a large role in the decision of which file system to adopt. There isn't any argument that NTFS offers better security and reliability. Some also say that NTFS is more flexible, but that can get rather subjective depending on the situation and work habits, whereas NTFS superiority in security and reliability is seldom challenged. Listed below are some of the most common factors to consider when deciding between FAT32 and NTFS.• Security
FAT32 provides very little security. A user with access to a drive using FAT32 has access to the files on that drive.NTFS allows the use of NTFS Permissions. It's much more difficult to implement, but folder and file access can be controlled individually, down to an an extreme degree if necessary. The down side of using NTFS Permissions is the chance for error and screwing up the system is greatly magnified.
Windows XP Professional supports file encryption.
• Compatibility
NTFS volumes are not recognized by Windows 95/98/Me. This is only a concern when the system is set up for dual or multi-booting. FAT32 must be be used for any drives that must be accessed when the computer is booted from Windows 95/98 or Windows Me.An additional note to the previous statement. Users on the network have access to shared folders no matter what disk format is being used or what version of Windows is installed.
FAT and FAT32 volumes can be converted to NTFS volumes. NTFS cannot be converted to FAT32 without reformatting.
• Space Efficiency
NTFS supports disk quotas, allowing you to control the amount of disk usage on a per user basis.NTFS supports file compression. FAT32 does not.
How a volume manages data is outside the scope of this article, but once you pass the 8GB partition size, NTFS handles space management much more efficiently than FAT32. Cluster sizes play an important part in how much disk space is wasted storing files. NTFS provides smaller cluster sizes and less disk space waste than FAT32.
In Windows XP, the maximum partition size that can be created using FAT32 is 32GB. This increases to 16TB (terabytes) using NTFS. There is a workaround for the 32GB limitation under FAT32, but it is a nuisance especially considering the size of drives currently being manufactured.
• Reliability
FAT32 drives are much more susceptible to disk errors.NTFS volumes have the ability to recover from errors more readily than similar FAT32 volumes.
Log files are created under NTFS which can be used for automatic file system repairs.
NTFS supports dynamic cluster remapping for bad sectors and prevent them from being used in the future.
The Final Choice
As the prior versions of Windows continue to age and are replaced in the home and workplace there will be no need for the older file systems. Hard drives aren't going to get smaller, networks are likely to get larger and more complex, and security is evolving almost daily as more and more users become connected. For all the innovations that Windows 95 brought to the desktop, it's now a virtual dinosaur. Windows 98 is fast on the way out and that leaves NT and Windows 2000, both well suited to NTFS. To wrap up, there may be compelling reasons why your current situation requires a file system other than NTFS or a combination of different systems for compatibility, but if at all possible go with NTFS. Even if you don't utilize its full scope of features, the stability and reliability it offers make it the hands down choice.
Sunday, February 21, 2010
NOVELL NETWARE
NetWare is a network operating system developed by Novell, Inc. It initially used cooperative multitasking to run various services on a personal computer, and the network protocols were based on the archetypal Xerox Network Systems stack.
NetWare has been superseded by Open Enterprise Server (OES). The latest version of NetWare is v6.5 Support Pack 8, which is identical to OES 2 SP1, NetWare Kernel.
History
NetWare evolved from a very simple concept: file sharing instead of disk sharing. In 1983 when the first versions of NetWare were designed, all other competing products were based on the concept of providing shared direct disk access. Novell's alternative approach was validated by IBM in 1984 and helped promote their product.
With Novell NetWare, disk space was shared in the form of NetWare volumes, comparable to DOS volumes. Clients running MS-DOS would run a special terminate and stay resident (TSR) program that allowed them to map a local drive letter to a NetWare volume. Clients had to log in to a server in order to be allowed to map volumes, and access could be restricted according to the login name. Similarly, they could connect to shared printers on the dedicated server, and print as if the printer was connected locally.
At the end of the 1990s, with Internet connectivity booming, the Internet's TCP/IP protocol became dominant on LANs. Novell had introduced limited TCP/IP support in NetWare v3.x (circa 1992) and v4.x (circa 1995), consisting mainly of FTP services and UNIX-style LPR/LPD printing (available in NetWare v3.x), and a Novell-developed webserver (in NetWare v4.x). Native TCP/IP support for the client file and print services normally associated with NetWare was introduced in NetWare v5.0 (released in 1998).
During the early-to-mid 1980s Microsoft introduced their own LAN system in LAN Manager based on the competing NBF protocol. Early attempts to muscle in on NetWare were not successful, but this changed with the inclusion of improved networking support in Windows for Workgroups, and then the hugely successful Windows NT and Windows 95. NT, in particular, offered services similar to those offered by NetWare, but on a system that could also be used on a desktop, and connected directly to other Windows desktops where NBF was now almost universal.
The rise of NetWare
The popular use and growth of Novell NetWare began in 1985 with the simultaneous release of NetWare 286 2.0a and the Intel 80286 16-bit processor. The 80286 CPU featured a new 16-bit protected mode that provided access to up to 16 MB RAM as well as new mechanisms to aid multi-tasking. Prior to the 80286 CPU servers were based on the Intel 8086/8088 8/16-bit processors, which were limited to an address space of 1MB with not more than 640 KB of directly addressable RAM.
The combination of a higher 16 MB RAM limit, 80286 processor feature utilization, and 256 MB NetWare volume size limit allowed reliable, cost-effective server-based local area networks to be built for the first time. The 16 MB RAM limit was especially important, since it made enough RAM available for disk caching to significantly improve performance. This became the key to Novell's performance while also allowing larger networks to be built.
Another significant difference of NetWare 286 was that it was hardware-independent, unlike competing server systems from 3Com. Novell servers could be assembled using any brand system with an Intel 80286 or higher CPU, any MFM, RLL, ESDI, or SCSI hard drive and any 8- or 16-bit network adapter for which Netware drivers were available.
Novell also designed a compact and simple DOS client software program that allowed DOS stations to connect to a server and access the shared server hard drive. While the NetWare server file system introduced a new, proprietary file system design, it looked like a standard DOS volume to the workstation, ensuring compatibility with all existing DOS programs.
Early years
NetWare was based on the consulting work by SuperSet Software, a group founded by the friends Drew Major, Dale Neibaur, Kyle Powell and later Mark Hurst. This work was based on their classwork at Brigham Young University in Provo, Utah, starting in October 1981.
In 1983, Raymond Noorda engaged the work by the SuperSet team. The team was originally assigned to create a CP/M disk sharing system to help network the CP/M hardware that Novell was selling at the time. The team was privately convinced that CP/M was a doomed platform and instead came up with a successful file sharing system for the newly introduced IBM-compatible PC. They also wrote an application called Snipes, a text-mode game and used it to test the new network and demonstrate its capabilities. Snipes was the first network application ever written for a commercial personal computer, and it is recognized as one of the precursors of many popular multiplayer games such as Doom and Quake.
This network operating system (NOS) was later called Novell NetWare. NetWare was based on the NetWare Core Protocol (NCP), which is a packet-based protocol that enables a client to send requests to and receive replies from a NetWare server. Initially NCP was directly tied to the IPX/SPX protocol, and NetWare communicated natively using only IPX/SPX.
The first product to bear the NetWare name was released in 1983. It was called Netware 68 (aka S-Net); it ran on the Motorola 68000 processor on a proprietary Novell-built file server and used a star network topology. This was soon joined by NetWare 86 V4.x, which was written for the Intel 8086. This was replaced in 1985 with Advanced NetWare 86 version 1.0a which allowed more than one server on the same network. In 1986, after the Intel 80286 processor became available, Novell released Advanced NetWare 286 V1.0a and subsequently V2.0B (that used IPX routing to allow up to 4 network cards in a server). In 1989, with the Intel 80386 available, Novell released NetWare 386. Later Novell consolidated the numbering of their NetWare releases, with NetWare 386 becoming NetWare 3.x.
NetWare 286 2.x
NetWare version 2 was notoriously difficult to configure, since the operating system was provided as a set of compiled object modules that required configuration and linking. Compounding this inconvenience was that the process was designed to run from multiple diskettes, which was slow and unreliable. Any change to the operating system required a re-linking of the kernel and a reboot of the system, requiring at least 20 diskette swaps. An additional complication in early versions was that the installation contained a proprietary low-level format program for MFM hard drives, which was run automatically before the software could be loaded, called COMPSURF.
NetWare was administered using text-based utilities such as SYSCON. The file system used by NetWare 2 was NetWare File System 286, or NWFS 286, supporting volumes of up to 256 MB. NetWare 286 recognized 80286 protected mode, extending NetWare's support of RAM from 1 MB to the full 16 MB addressable by the 80286. A minimum of 2 MB was required to start up the operating system; any additional RAM was used for FAT, DET and file caching. Since 16-bit protected mode was implemented the i80286 and every subsequent Intel x86 processor, NetWare 286 version 2.x would run on any 80286 or later compatible processor.
NetWare 2 implemented a number of features inspired by mainframe and minicomputer systems that were not available in other operating systems of the day. The System Fault Tolerance (SFT) features included standard read-after-write verification (SFT-I) with on-the-fly bad block re-mapping (at the time, disks did not have that feature built in) and software RAID1 (disk mirroring, SFT-II). The Transaction Tracking System (TTS) optionally protected files against incomplete updates. For single files, this required only a file attribute to be set. Transactions over multiple files and controlled roll-backs were possible by programming to the TTS API.
NetWare 286 2.x supported two modes of operation: dedicated and non-dedicated. In dedicated mode, the server used DOS only as a boot loader to execute the operating system file net$os.exe. All memory was allocated to NetWare; no DOS ran on the server. For non-dedicated operation, DOS 3.3 or higher would remain in memory, and the processor would time-slice between the DOS and NetWare programs, allowing the server computer to be used simultaneously as network file server and as a user workstation. All extended memory (RAM above 1 MB) was allocated to NetWare, so DOS was limited to only 640kB; an expanded memory manager would not work because NetWare 286 had control of 80286 protected mode and the upper RAM, both of which were required for DOS to use expanded memory. Time slicing was accomplished using the keyboard interrupt. This feature required strict compliance with the IBM PC design model, otherwise performance was affected. Non-dedicated NetWare was popular on small networks, although it was more susceptible to lockups due to DOS program problems. In some implementations, users would experience significant network slowdown when someone was using the console as a workstation. NetWare 386 3.x and later supported only dedicated operation.
Server licensing on early versions of NetWare 286 was accomplished by using a key card. The key card was designed for an 8-bit ISA bus, and had a serial number encoded on a ROM chip. The serial number had to match the serial number of the NetWare software running on the server. To broaden the hardware base, particularly to machines using the IBM MCA bus, later versions of NetWare 2.x did not require the key card; serialised license floppy disks were used in place of the key cards.
NetWare 3.x
Starting with NetWare 3.x, support for 32-bit protected mode was added, eliminating the 16 mb memory limit of NetWare 286. This allowed larger hard drives to be supported, since NetWare 3.x cached (copied) the entire file allocation table (FAT) and directory entry table (DET) into memory for improved performance.
By accident or design, the initial releases of the client TSR programs modified the high 16 bits of the 32-bit 80386 registers, making them unusable by any other program until this was fixed. The problem was noticed by Phil Katz who added a switch to his PKZIP suite of programs to enable 32-bit register use only when the Netware TSRs were not present.
NetWare version 3 eased development and administration by modularization. Each functionality was controlled by a software module called a NetWare Loadable Module (NLM) loaded either at startup or when it was needed. It was then possible to add functionality such as anti-virus software, backup software, database and web servers, long name support (standard filenames were limited to 8 characters plus a three letter extension, matching MS-DOS) or Macintosh style files.
NetWare continued to be administered using console-based utilities. The file system introduced by NetWare 3.x and used by default until NetWare 5.x was NetWare File System 386, or NWFS 386, which significantly extended volume capacity (1 TB, 4 GB files) and could handle up to 16 volume segments spanning multiple physical disk drives. Volume segments could be added while the server was in use and the volume was mounted, allowing a server to be expanded without interruption.
Initially, NetWare used Bindery services for authentication. This was a stand-alone database system where all user access and security data resided individually on each server. When an infrastructure contained more than one server, users had to log-in to each of them individually, and each server had to be configured with the list of all allowed users.
"NetWare Name Services" was a product that allowed user data to be extended across multiple servers, and the Windows "Domain" concept is functionally equivalent to NetWare v3.x Bindery services with NetWare Name Services added on (e.g. a 2-dimensional database, with a flat namespace and a static schema).
For a while, Novell also marketed an OEM version of NetWare 3, called Portable NetWare, together with OEMs such as Hewlett-Packard, DEC and Data General, who ported Novell source code to run on top of their Unix operating systems. Portable NetWare did not sell well.
While Netware 3.x was current, Novell introduced its first high-availability clustering system, named NetWare SFT-III, which allowed a logical server to be completely mirrored to a separate physical machine. Implemented as a shared-nothing cluster, under SFT-III the OS was logically split into an interrupt-driven I/O engine and the event-driven OS core. The I/O engines serialized their interrupts (disk, network etc.) into a combined event stream that was fed to two identical copies of the system engine through a fast (typically 100 Mbit/s) inter-server link. Because of its non-preemptive nature, the OS core, stripped of non-deterministic I/O, behaves deterministically, like a large finite state machine.
The outputs of the two system engines were compared to ensure proper operation, and two copies fed back to the I/O engines. Using the existing SFT-II software RAID functionality present in the core, disks could be mirrored between the two machines without special hardware. The two machines could be separated as far as the server-to-server link would permit. In case of a server or disk failure, the surviving server could take over client sessions transparently after a short pause since it had full state information and did not, for example, have to re-mount the volumes - a process at which NetWare was notoriously slow. SFT-III was the first NetWare version able to make use of SMP hardware - the I/O engine could optionally be run on its own CPU. The modern incarnation of NetWare's clustering, Novell Cluster Services (introduced in NetWare v5.0), is very different from SFT-III. NetWare SFT-III, ahead of its time in several ways, was a mixed success.
NetWare 386 3.x was designed to run all applications on the server at the same level of processor memory protection, known as "ring 0". While this provided the best possible performance, it sacrificed reliability. The result was that crashing (known as abends, short for abnormal ends) were possible and would result in stopping the system. Starting with NetWare 5.x, software modules (NetWare Loadable Modules or NLM's) could be assigned to run in different processor protection rings, ensuring that a software error would not crash the system.
NetWare 4.x
Version 4 in 1993 also introduced NetWare Directory Services, later re-branded as Novell Directory Services (NDS), based on X.500, which replaced the Bindery with a global directory service, in which the infrastructure was described and managed in a single place. Additionally, NDS provided an extensible schema, allowing the introduction of new object types. This allowed a single user authentication to NDS to govern access to any server in the directory tree structure. Users could therefore access network resources no matter on which server they resided, although user license counts were still tied to individual servers. (Large enterprises could opt for a license model giving them essentially unlimited per-server users if they let Novell audit their total user count)
Version 4 also introduced a number of useful tools and features, such as transparent compression at file system level and RSA public/private encryption.
Another new feature was the NetWare Asynchronous Services Interface (NASI). It allowed network sharing of multiple serial devices, such as modems. Client port redirection occurred via an MS-DOS or Microsoft Windows driver allowing companies to consolidate modems and analog phone lines
Strategic mistakes
Novell's strategy with NetWare 286 2.x and 3.x was very successful; before the arrival of Windows NT Server, Novell claimed 90% of the market for PC based servers.
While the design of NetWare 3.x and later involved a DOS partition to load NetWare server files, this feature became a liability as new users preferred the Windows graphical interface to learning DOS commands necessary to build and control a NetWare server. Novell could have eliminated this technical liability by retaining the design of NetWare 286, which installed the server file into a Novell partition and allowed the server to boot from the Novell partition without creating a bootable DOS partition. Novell finally added support for this in a Support Pack for NetWare 6.5.
As Novell used IPX/SPX instead of TCP/IP, they were poorly positioned to take advantage of the Internet in 1995. This resulted in Novell servers being bypassed for routing and Internet access, in favor of hardware routers, Unix-based operating systems such as FreeBSD, and SOCKS and HTTP Proxy Servers on Windows and other operating systems
NetWare 4.1x and NetWare for Small Business: Novell begins to recover
Novell priced NetWare 4.10 similarly to NetWare 3.12, allowing customers who resisted NDS (typically small businesses) to try it at no cost.
Later Novell released NetWare version 4.11 in 1996 which included many enhancements that made the operating system easier to install, easier to operate, faster, and more stable. It also included the first full 32-bit client for Microsoft Windows-based workstations, SMP support and the NetWare Administrator (NWADMIN or NWADMN32), a GUI-based administration tool for NetWare. Previous administration tools used the Cworthy interface, the character-based GUI tools such as SYSCON and PCONSOLE with blue text-based background. Some of these tools survive to this day, for instance MONITOR.NLM.
Novell packaged NetWare 4.11 with its Web server, TCP/IP support and Netscape browser into a bundle dubbed IntranetWare (also written as intraNetWare). A version designed for networks of 25 or fewer users was named IntranetWare for Small Business and contained a limited version of NDS and tried to simplify NDS administration. The intranetWare name was dropped in NetWare 5.
During this time Novell also began to leverage its directory service, NDS, by tying their other products into the directory. Their e-mail system, GroupWise, was integrated with NDS, and Novell released many other directory-enabled products such as ZENworks and BorderManager.
NetWare still required IPX/SPX as NCP used it, but Novell started to acknowledge the demand for TCP/IP with NetWare 4.11 by including tools and utilities that made it easier to create intranets and link networks to the Internet. Novell bundled tools, such as the IPX/IP gateway, to ease the connection between IPX workstations and IP networks. It also began integrating Internet technologies and support through features such as a natively hosted web server.
NetWare 5.x
With the release of NetWare 5 in October 1998, Novell finally acknowledged the prominence of the Internet by switching its primary NCP interface from the IPX/SPX network protocol to TCP/IP. IPX/SPX was still supported, but the emphasis shifted to TCP/IP. Novell also added a GUI to NetWare. Other new features were:
Novell Storage Services (NSS), a new file system to replace the traditional NetWare File System - which was still supported
Java virtual machine for NetWare
Novell Distributed Print Services (NDPS)
ConsoleOne, a new Java-based GUI administration console
directory-enabled Public key infrastructure services (PKIS)
directory-enabled DNS and DHCP servers
support for Storage Area Networks (SANs)
Novell Cluster Services (NCS)
Oracle 8i with a 5-user license
The Cluster Services were a major advance over SFT-III, as NCS does not require specialized hardware or identical server configurations.
NetWare 5 was released during a time when NetWare market share dropped precipitously; many companies and organizations were replacing their NetWare servers with servers running Microsoft's Windows NT operating system. Novell also released their last upgrade to the NetWare 4 operating system, NetWare 4.2.
NetWare 5.1 was released in January 2000, shortly after its predecessor. It introduced a number of useful tools, such as:
IBM WebSphere Application Server
NetWare Management Portal (later renamed Novell Remote Manager), web-based management of the operating system
FTP, NNTP and streaming media servers
NetWare Web Search Server
WebDAV support
NetWare 6.0
NetWare 6 was released in October 2001. This version has a simplified licensing scheme based on users, not servers. This allows unlimited connections per user.
NetWare 6.5
NetWare 6.5 was released in August 2003. Some of the new features in this version were:
more open-source products such as PHP, MySQL and OpenSSH
a port of the Bash shell and a lot of traditional Unix utilities such as wget, grep, awk and sed to provide additional capabilities for scripting
iSCSI support (both target and initiator)
Virtual Office - an "out of the box" web portal for end users providing access to e-mail, personal file storage, company address book, etc.
Domain controller functionality
Universal password
DirXML Starter Pack - synchronization of user accounts with another eDirectory tree, a Windows NT domain or Active Directory.
exteNd Application Server - a J2EE 1.3-compatible application server
support for customized printer driver profiles and printer usage auditing
NX bit support
support for USB storage devices
support for encrypted volumes
The latest - and apparently last - Service Pack for Netware 6.5 is SP8, released October 2008.
Open Enterprise Server
1.0
In 2003, Novell announced the successor product to NetWare: Open Enterprise Server (OES). First released in March 2005, OES completes the separation of the services traditionally associated with NetWare (e.g. Directory Services, file-and-print) from the platform underlying the delivery of those services. OES is essentially a set of applications (eDirectory, NetWare Core Protocol services, iPrint, etc.) that can run atop either a Linux or a NetWare kernel platform. Clustered OES implementations can even migrate services from Linux to NetWare and back again, making Novell one of the very few vendors to offer a multi-platform clustering solution.
Consequent to Novell's acquisitions of Ximian and SuSE, a German Linux distributor, it is widely observed that Novell is moving away from NetWare and shifting its focus towards Linux. Much recent marketing seems to be focussed on getting faithful NetWare users to move to the Linux platform in future releases.The clearest indication of this direction is Novell's controversial decision to release Open Enterprise Server in Linux form only. Novell later watered down this decision and stated that NetWare's 90 million users would be supported until at least 2015.Some of Novell's more perverse NetWare supporters have taken it upon themselves to petition Novell to keep NetWare in development
2.0
OES 2 was released on October 8, 2007. It includes NetWare 6.5 SP7, which supports running as a paravirtualized guest inside the Xen hypervisor and new Linux based version using SLES10.
New features include
64bit support
Virtualization
Dynamic Storage Technology, which provide Shadow Volumes
Domain services for Windows (provided in OES 2 service pack 1)
Current NetWare situation
While Novell NetWare is still used by some organizations, its ongoing decline in popularity began in the mid-1990s, when NetWare was the de facto standard for file and print software for the Intel x86 server platform. Modern (2009) NetWare and OES installations are used by larger organizations that may need the added flexibility they provide.
Microsoft successfully shifted market share away from NetWare products toward their own in the late-1990s. Microsoft's more aggressive marketing was aimed directly to management through major magazines; Novell NetWare's was through IT specialist magazines with distribution limited to select IT personnel.
Novell did not adapt their pricing structure accordingly and NetWare sales suffered at the hands of those corporate decision makers whose valuation was based on initial licensing fees. As a result organizations that still use NetWare, eDirectory, and Novell software often have a hybrid infrastructure of NetWare, Linux, and Windows servers.
NetWare has been superseded by Open Enterprise Server (OES). The latest version of NetWare is v6.5 Support Pack 8, which is identical to OES 2 SP1, NetWare Kernel.
History
NetWare evolved from a very simple concept: file sharing instead of disk sharing. In 1983 when the first versions of NetWare were designed, all other competing products were based on the concept of providing shared direct disk access. Novell's alternative approach was validated by IBM in 1984 and helped promote their product.
With Novell NetWare, disk space was shared in the form of NetWare volumes, comparable to DOS volumes. Clients running MS-DOS would run a special terminate and stay resident (TSR) program that allowed them to map a local drive letter to a NetWare volume. Clients had to log in to a server in order to be allowed to map volumes, and access could be restricted according to the login name. Similarly, they could connect to shared printers on the dedicated server, and print as if the printer was connected locally.
At the end of the 1990s, with Internet connectivity booming, the Internet's TCP/IP protocol became dominant on LANs. Novell had introduced limited TCP/IP support in NetWare v3.x (circa 1992) and v4.x (circa 1995), consisting mainly of FTP services and UNIX-style LPR/LPD printing (available in NetWare v3.x), and a Novell-developed webserver (in NetWare v4.x). Native TCP/IP support for the client file and print services normally associated with NetWare was introduced in NetWare v5.0 (released in 1998).
During the early-to-mid 1980s Microsoft introduced their own LAN system in LAN Manager based on the competing NBF protocol. Early attempts to muscle in on NetWare were not successful, but this changed with the inclusion of improved networking support in Windows for Workgroups, and then the hugely successful Windows NT and Windows 95. NT, in particular, offered services similar to those offered by NetWare, but on a system that could also be used on a desktop, and connected directly to other Windows desktops where NBF was now almost universal.
The rise of NetWare
The popular use and growth of Novell NetWare began in 1985 with the simultaneous release of NetWare 286 2.0a and the Intel 80286 16-bit processor. The 80286 CPU featured a new 16-bit protected mode that provided access to up to 16 MB RAM as well as new mechanisms to aid multi-tasking. Prior to the 80286 CPU servers were based on the Intel 8086/8088 8/16-bit processors, which were limited to an address space of 1MB with not more than 640 KB of directly addressable RAM.
The combination of a higher 16 MB RAM limit, 80286 processor feature utilization, and 256 MB NetWare volume size limit allowed reliable, cost-effective server-based local area networks to be built for the first time. The 16 MB RAM limit was especially important, since it made enough RAM available for disk caching to significantly improve performance. This became the key to Novell's performance while also allowing larger networks to be built.
Another significant difference of NetWare 286 was that it was hardware-independent, unlike competing server systems from 3Com. Novell servers could be assembled using any brand system with an Intel 80286 or higher CPU, any MFM, RLL, ESDI, or SCSI hard drive and any 8- or 16-bit network adapter for which Netware drivers were available.
Novell also designed a compact and simple DOS client software program that allowed DOS stations to connect to a server and access the shared server hard drive. While the NetWare server file system introduced a new, proprietary file system design, it looked like a standard DOS volume to the workstation, ensuring compatibility with all existing DOS programs.
Early years
NetWare was based on the consulting work by SuperSet Software, a group founded by the friends Drew Major, Dale Neibaur, Kyle Powell and later Mark Hurst. This work was based on their classwork at Brigham Young University in Provo, Utah, starting in October 1981.
In 1983, Raymond Noorda engaged the work by the SuperSet team. The team was originally assigned to create a CP/M disk sharing system to help network the CP/M hardware that Novell was selling at the time. The team was privately convinced that CP/M was a doomed platform and instead came up with a successful file sharing system for the newly introduced IBM-compatible PC. They also wrote an application called Snipes, a text-mode game and used it to test the new network and demonstrate its capabilities. Snipes was the first network application ever written for a commercial personal computer, and it is recognized as one of the precursors of many popular multiplayer games such as Doom and Quake.
This network operating system (NOS) was later called Novell NetWare. NetWare was based on the NetWare Core Protocol (NCP), which is a packet-based protocol that enables a client to send requests to and receive replies from a NetWare server. Initially NCP was directly tied to the IPX/SPX protocol, and NetWare communicated natively using only IPX/SPX.
The first product to bear the NetWare name was released in 1983. It was called Netware 68 (aka S-Net); it ran on the Motorola 68000 processor on a proprietary Novell-built file server and used a star network topology. This was soon joined by NetWare 86 V4.x, which was written for the Intel 8086. This was replaced in 1985 with Advanced NetWare 86 version 1.0a which allowed more than one server on the same network. In 1986, after the Intel 80286 processor became available, Novell released Advanced NetWare 286 V1.0a and subsequently V2.0B (that used IPX routing to allow up to 4 network cards in a server). In 1989, with the Intel 80386 available, Novell released NetWare 386. Later Novell consolidated the numbering of their NetWare releases, with NetWare 386 becoming NetWare 3.x.
NetWare 286 2.x
NetWare version 2 was notoriously difficult to configure, since the operating system was provided as a set of compiled object modules that required configuration and linking. Compounding this inconvenience was that the process was designed to run from multiple diskettes, which was slow and unreliable. Any change to the operating system required a re-linking of the kernel and a reboot of the system, requiring at least 20 diskette swaps. An additional complication in early versions was that the installation contained a proprietary low-level format program for MFM hard drives, which was run automatically before the software could be loaded, called COMPSURF.
NetWare was administered using text-based utilities such as SYSCON. The file system used by NetWare 2 was NetWare File System 286, or NWFS 286, supporting volumes of up to 256 MB. NetWare 286 recognized 80286 protected mode, extending NetWare's support of RAM from 1 MB to the full 16 MB addressable by the 80286. A minimum of 2 MB was required to start up the operating system; any additional RAM was used for FAT, DET and file caching. Since 16-bit protected mode was implemented the i80286 and every subsequent Intel x86 processor, NetWare 286 version 2.x would run on any 80286 or later compatible processor.
NetWare 2 implemented a number of features inspired by mainframe and minicomputer systems that were not available in other operating systems of the day. The System Fault Tolerance (SFT) features included standard read-after-write verification (SFT-I) with on-the-fly bad block re-mapping (at the time, disks did not have that feature built in) and software RAID1 (disk mirroring, SFT-II). The Transaction Tracking System (TTS) optionally protected files against incomplete updates. For single files, this required only a file attribute to be set. Transactions over multiple files and controlled roll-backs were possible by programming to the TTS API.
NetWare 286 2.x supported two modes of operation: dedicated and non-dedicated. In dedicated mode, the server used DOS only as a boot loader to execute the operating system file net$os.exe. All memory was allocated to NetWare; no DOS ran on the server. For non-dedicated operation, DOS 3.3 or higher would remain in memory, and the processor would time-slice between the DOS and NetWare programs, allowing the server computer to be used simultaneously as network file server and as a user workstation. All extended memory (RAM above 1 MB) was allocated to NetWare, so DOS was limited to only 640kB; an expanded memory manager would not work because NetWare 286 had control of 80286 protected mode and the upper RAM, both of which were required for DOS to use expanded memory. Time slicing was accomplished using the keyboard interrupt. This feature required strict compliance with the IBM PC design model, otherwise performance was affected. Non-dedicated NetWare was popular on small networks, although it was more susceptible to lockups due to DOS program problems. In some implementations, users would experience significant network slowdown when someone was using the console as a workstation. NetWare 386 3.x and later supported only dedicated operation.
Server licensing on early versions of NetWare 286 was accomplished by using a key card. The key card was designed for an 8-bit ISA bus, and had a serial number encoded on a ROM chip. The serial number had to match the serial number of the NetWare software running on the server. To broaden the hardware base, particularly to machines using the IBM MCA bus, later versions of NetWare 2.x did not require the key card; serialised license floppy disks were used in place of the key cards.
NetWare 3.x
Starting with NetWare 3.x, support for 32-bit protected mode was added, eliminating the 16 mb memory limit of NetWare 286. This allowed larger hard drives to be supported, since NetWare 3.x cached (copied) the entire file allocation table (FAT) and directory entry table (DET) into memory for improved performance.
By accident or design, the initial releases of the client TSR programs modified the high 16 bits of the 32-bit 80386 registers, making them unusable by any other program until this was fixed. The problem was noticed by Phil Katz who added a switch to his PKZIP suite of programs to enable 32-bit register use only when the Netware TSRs were not present.
NetWare version 3 eased development and administration by modularization. Each functionality was controlled by a software module called a NetWare Loadable Module (NLM) loaded either at startup or when it was needed. It was then possible to add functionality such as anti-virus software, backup software, database and web servers, long name support (standard filenames were limited to 8 characters plus a three letter extension, matching MS-DOS) or Macintosh style files.
NetWare continued to be administered using console-based utilities. The file system introduced by NetWare 3.x and used by default until NetWare 5.x was NetWare File System 386, or NWFS 386, which significantly extended volume capacity (1 TB, 4 GB files) and could handle up to 16 volume segments spanning multiple physical disk drives. Volume segments could be added while the server was in use and the volume was mounted, allowing a server to be expanded without interruption.
Initially, NetWare used Bindery services for authentication. This was a stand-alone database system where all user access and security data resided individually on each server. When an infrastructure contained more than one server, users had to log-in to each of them individually, and each server had to be configured with the list of all allowed users.
"NetWare Name Services" was a product that allowed user data to be extended across multiple servers, and the Windows "Domain" concept is functionally equivalent to NetWare v3.x Bindery services with NetWare Name Services added on (e.g. a 2-dimensional database, with a flat namespace and a static schema).
For a while, Novell also marketed an OEM version of NetWare 3, called Portable NetWare, together with OEMs such as Hewlett-Packard, DEC and Data General, who ported Novell source code to run on top of their Unix operating systems. Portable NetWare did not sell well.
While Netware 3.x was current, Novell introduced its first high-availability clustering system, named NetWare SFT-III, which allowed a logical server to be completely mirrored to a separate physical machine. Implemented as a shared-nothing cluster, under SFT-III the OS was logically split into an interrupt-driven I/O engine and the event-driven OS core. The I/O engines serialized their interrupts (disk, network etc.) into a combined event stream that was fed to two identical copies of the system engine through a fast (typically 100 Mbit/s) inter-server link. Because of its non-preemptive nature, the OS core, stripped of non-deterministic I/O, behaves deterministically, like a large finite state machine.
The outputs of the two system engines were compared to ensure proper operation, and two copies fed back to the I/O engines. Using the existing SFT-II software RAID functionality present in the core, disks could be mirrored between the two machines without special hardware. The two machines could be separated as far as the server-to-server link would permit. In case of a server or disk failure, the surviving server could take over client sessions transparently after a short pause since it had full state information and did not, for example, have to re-mount the volumes - a process at which NetWare was notoriously slow. SFT-III was the first NetWare version able to make use of SMP hardware - the I/O engine could optionally be run on its own CPU. The modern incarnation of NetWare's clustering, Novell Cluster Services (introduced in NetWare v5.0), is very different from SFT-III. NetWare SFT-III, ahead of its time in several ways, was a mixed success.
NetWare 386 3.x was designed to run all applications on the server at the same level of processor memory protection, known as "ring 0". While this provided the best possible performance, it sacrificed reliability. The result was that crashing (known as abends, short for abnormal ends) were possible and would result in stopping the system. Starting with NetWare 5.x, software modules (NetWare Loadable Modules or NLM's) could be assigned to run in different processor protection rings, ensuring that a software error would not crash the system.
NetWare 4.x
Version 4 in 1993 also introduced NetWare Directory Services, later re-branded as Novell Directory Services (NDS), based on X.500, which replaced the Bindery with a global directory service, in which the infrastructure was described and managed in a single place. Additionally, NDS provided an extensible schema, allowing the introduction of new object types. This allowed a single user authentication to NDS to govern access to any server in the directory tree structure. Users could therefore access network resources no matter on which server they resided, although user license counts were still tied to individual servers. (Large enterprises could opt for a license model giving them essentially unlimited per-server users if they let Novell audit their total user count)
Version 4 also introduced a number of useful tools and features, such as transparent compression at file system level and RSA public/private encryption.
Another new feature was the NetWare Asynchronous Services Interface (NASI). It allowed network sharing of multiple serial devices, such as modems. Client port redirection occurred via an MS-DOS or Microsoft Windows driver allowing companies to consolidate modems and analog phone lines
Strategic mistakes
Novell's strategy with NetWare 286 2.x and 3.x was very successful; before the arrival of Windows NT Server, Novell claimed 90% of the market for PC based servers.
While the design of NetWare 3.x and later involved a DOS partition to load NetWare server files, this feature became a liability as new users preferred the Windows graphical interface to learning DOS commands necessary to build and control a NetWare server. Novell could have eliminated this technical liability by retaining the design of NetWare 286, which installed the server file into a Novell partition and allowed the server to boot from the Novell partition without creating a bootable DOS partition. Novell finally added support for this in a Support Pack for NetWare 6.5.
As Novell used IPX/SPX instead of TCP/IP, they were poorly positioned to take advantage of the Internet in 1995. This resulted in Novell servers being bypassed for routing and Internet access, in favor of hardware routers, Unix-based operating systems such as FreeBSD, and SOCKS and HTTP Proxy Servers on Windows and other operating systems
NetWare 4.1x and NetWare for Small Business: Novell begins to recover
Novell priced NetWare 4.10 similarly to NetWare 3.12, allowing customers who resisted NDS (typically small businesses) to try it at no cost.
Later Novell released NetWare version 4.11 in 1996 which included many enhancements that made the operating system easier to install, easier to operate, faster, and more stable. It also included the first full 32-bit client for Microsoft Windows-based workstations, SMP support and the NetWare Administrator (NWADMIN or NWADMN32), a GUI-based administration tool for NetWare. Previous administration tools used the Cworthy interface, the character-based GUI tools such as SYSCON and PCONSOLE with blue text-based background. Some of these tools survive to this day, for instance MONITOR.NLM.
Novell packaged NetWare 4.11 with its Web server, TCP/IP support and Netscape browser into a bundle dubbed IntranetWare (also written as intraNetWare). A version designed for networks of 25 or fewer users was named IntranetWare for Small Business and contained a limited version of NDS and tried to simplify NDS administration. The intranetWare name was dropped in NetWare 5.
During this time Novell also began to leverage its directory service, NDS, by tying their other products into the directory. Their e-mail system, GroupWise, was integrated with NDS, and Novell released many other directory-enabled products such as ZENworks and BorderManager.
NetWare still required IPX/SPX as NCP used it, but Novell started to acknowledge the demand for TCP/IP with NetWare 4.11 by including tools and utilities that made it easier to create intranets and link networks to the Internet. Novell bundled tools, such as the IPX/IP gateway, to ease the connection between IPX workstations and IP networks. It also began integrating Internet technologies and support through features such as a natively hosted web server.
NetWare 5.x
With the release of NetWare 5 in October 1998, Novell finally acknowledged the prominence of the Internet by switching its primary NCP interface from the IPX/SPX network protocol to TCP/IP. IPX/SPX was still supported, but the emphasis shifted to TCP/IP. Novell also added a GUI to NetWare. Other new features were:
Novell Storage Services (NSS), a new file system to replace the traditional NetWare File System - which was still supported
Java virtual machine for NetWare
Novell Distributed Print Services (NDPS)
ConsoleOne, a new Java-based GUI administration console
directory-enabled Public key infrastructure services (PKIS)
directory-enabled DNS and DHCP servers
support for Storage Area Networks (SANs)
Novell Cluster Services (NCS)
Oracle 8i with a 5-user license
The Cluster Services were a major advance over SFT-III, as NCS does not require specialized hardware or identical server configurations.
NetWare 5 was released during a time when NetWare market share dropped precipitously; many companies and organizations were replacing their NetWare servers with servers running Microsoft's Windows NT operating system. Novell also released their last upgrade to the NetWare 4 operating system, NetWare 4.2.
NetWare 5.1 was released in January 2000, shortly after its predecessor. It introduced a number of useful tools, such as:
IBM WebSphere Application Server
NetWare Management Portal (later renamed Novell Remote Manager), web-based management of the operating system
FTP, NNTP and streaming media servers
NetWare Web Search Server
WebDAV support
NetWare 6.0
NetWare 6 was released in October 2001. This version has a simplified licensing scheme based on users, not servers. This allows unlimited connections per user.
NetWare 6.5
NetWare 6.5 was released in August 2003. Some of the new features in this version were:
more open-source products such as PHP, MySQL and OpenSSH
a port of the Bash shell and a lot of traditional Unix utilities such as wget, grep, awk and sed to provide additional capabilities for scripting
iSCSI support (both target and initiator)
Virtual Office - an "out of the box" web portal for end users providing access to e-mail, personal file storage, company address book, etc.
Domain controller functionality
Universal password
DirXML Starter Pack - synchronization of user accounts with another eDirectory tree, a Windows NT domain or Active Directory.
exteNd Application Server - a J2EE 1.3-compatible application server
support for customized printer driver profiles and printer usage auditing
NX bit support
support for USB storage devices
support for encrypted volumes
The latest - and apparently last - Service Pack for Netware 6.5 is SP8, released October 2008.
Open Enterprise Server
1.0
In 2003, Novell announced the successor product to NetWare: Open Enterprise Server (OES). First released in March 2005, OES completes the separation of the services traditionally associated with NetWare (e.g. Directory Services, file-and-print) from the platform underlying the delivery of those services. OES is essentially a set of applications (eDirectory, NetWare Core Protocol services, iPrint, etc.) that can run atop either a Linux or a NetWare kernel platform. Clustered OES implementations can even migrate services from Linux to NetWare and back again, making Novell one of the very few vendors to offer a multi-platform clustering solution.
Consequent to Novell's acquisitions of Ximian and SuSE, a German Linux distributor, it is widely observed that Novell is moving away from NetWare and shifting its focus towards Linux. Much recent marketing seems to be focussed on getting faithful NetWare users to move to the Linux platform in future releases.The clearest indication of this direction is Novell's controversial decision to release Open Enterprise Server in Linux form only. Novell later watered down this decision and stated that NetWare's 90 million users would be supported until at least 2015.Some of Novell's more perverse NetWare supporters have taken it upon themselves to petition Novell to keep NetWare in development
2.0
OES 2 was released on October 8, 2007. It includes NetWare 6.5 SP7, which supports running as a paravirtualized guest inside the Xen hypervisor and new Linux based version using SLES10.
New features include
64bit support
Virtualization
Dynamic Storage Technology, which provide Shadow Volumes
Domain services for Windows (provided in OES 2 service pack 1)
Current NetWare situation
While Novell NetWare is still used by some organizations, its ongoing decline in popularity began in the mid-1990s, when NetWare was the de facto standard for file and print software for the Intel x86 server platform. Modern (2009) NetWare and OES installations are used by larger organizations that may need the added flexibility they provide.
Microsoft successfully shifted market share away from NetWare products toward their own in the late-1990s. Microsoft's more aggressive marketing was aimed directly to management through major magazines; Novell NetWare's was through IT specialist magazines with distribution limited to select IT personnel.
Novell did not adapt their pricing structure accordingly and NetWare sales suffered at the hands of those corporate decision makers whose valuation was based on initial licensing fees. As a result organizations that still use NetWare, eDirectory, and Novell software often have a hybrid infrastructure of NetWare, Linux, and Windows servers.
Monday, February 15, 2010
PROCESS SCHEDULING
Scheduling is a key concept in computer multitasking, multiprocessing operating system and real-time operating system designs. Scheduling refers to the way processes are assigned to run on the available CPUs, since there are typically many more processes running than there are available CPUs. This assignment is carried out by software known as a scheduler or dispatcher.
The scheduler is concerned mainly with:
CPU utilization - to keep the CPU as busy as possible.
Throughput - number of processes that complete their execution per time unit.
Turnaround - total time between submission of a process and its completion.
Waiting time - amount of time a process has been waiting in the ready queue.
Response time - amount of time it takes from when a request was submitted until the first response is produced.
Fairness - Equal CPU time to each thread.
In real-time environments, such as mobile devices for automatic control in industry (for example robotics), the scheduler also must ensure that processes can meet deadlines; this is crucial for keeping the system stable. Scheduled tasks are sent to mobile devices and managed through an administrative back end.
Types of operating system schedulers
Operating systems may feature up to 3 distinct types of schedulers: a long-term scheduler (also known as an admission scheduler or high-level scheduler), a mid-term or medium-term scheduler and a short-term scheduler (also known as a dispatcher). The names suggest the relative frequency with which these functions are performed.
Long-term Scheduler
The long-term, or admission, scheduler decides which jobs or processes are to be admitted to the ready queue; that is, when an attempt is made to execute a program, its admission to the set of currently executing processes is either authorized or delayed by the long-term scheduler. Thus, this scheduler dictates what processes are to run on a system, and the degree of concurrency to be supported at any one time - ie: whether a high or low amount of processes are to be executed concurrently, and how the split between IO intensive and CPU intensive processes is to be handled. In modern OS's, this is used to make sure that real time processes get enough CPU time to finish their tasks. Without proper real time scheduling, modern GUI interfaces would seem sluggish. [Stallings, 399].1
Long-term scheduling is also important in large-scale systems such as batch processing systems, computer clusters, supercomputers and render farms. In these cases, special purpose job scheduler software is typically used to assist these functions, in addition to any underlying admission scheduling support in the operating system.
Mid-term Scheduler
The mid-term scheduler temporarily removes processes from main memory and places them on secondary memory (such as a disk drive) or vice versa. This is commonly referred to as "swapping out" or "swapping in" (also incorrectly as "paging out" or "paging in"). The mid-term scheduler may decide to swap out a process which has not been active for some time, or a process which has a low priority, or a process which is page faulting frequently, or a process which is taking up a large amount of memory in order to free up main memory for other processes, swapping the process back in later when more memory is available, or when the process has been unblocked and is no longer waiting for a resource. [Stallings, 396] [Stallings, 370]
In many systems today (those that support mapping virtual address space to secondary storage other than the swap file), the mid-term scheduler may actually perform the role of the long-term scheduler, by treating binaries as "swapped out processes" upon their execution. In this way, when a segment of the binary is required it can be swapped in on demand, or "lazy loaded".
Short-term Scheduler
The short-term scheduler (also known as the CPU scheduler) decides which of the ready, in-memory processes are to be executed (allocated a CPU) next following a clock interrupt, an IO interrupt, an operating system call or another form of signal. Thus the short-term scheduler makes scheduling decisions much more frequently than the long-term or mid-term schedulers - a scheduling decision will at a minimum have to be made after every time slice, and these are very short. This scheduler can be preemptive, implying that it is capable of forcibly removing processes from a CPU when it decides to allocate that CPU to another process, or non-preemptive (also known as "voluntary" or "co-operative"), in which case the scheduler is unable to "force" processes off the CPU.
Dispatcher
Another component involved in the CPU-scheduling function is the dispatcher. The dispatcher is the module that gives control of the CPU to the process selected by the short-term scheduler. This function involves the following:
Switching context
Switching to user mode
Jumping to the proper location in the user program to restart that program
The dispatcher should be as fast as possible, since it is invoked during every process switch. The time it takes for the dispatcher to stop one process and start another running is known as the dispatch latency.
Scheduling criteria
Different CPU scheduling algorithms have different properties, and the choice of a particular algorithm may favor one class of processes over another. In choosing which algorithm to use in a particular situation, we must consider the properties of the various algorithms. Many criteria have been suggested for comparing CPU scheduling algorithms. Which characteristics are used for comparison can make a substantial difference in which algorithm is judged to be best. The criteria include the following:
CPU Utilization. We want to keep the CPU as busy as possible.
Throughput. If the CPU is busy executing processes, then work is being done. One measure of work is the number of processes that are completed per time unit, called throughput. For long processes, this rate may be one process per hour; for short transactions, it may be 10 processes per second.
Turnaround time. From the point of view of a particular process, the important criterion is how long it takes to execute that process. The interval from the time of submission of a process to the time of completion is the turnaround time. Turnaround time is the sum of the periods spent waiting to get into memory, waiting in the ready queue, executing on the CPU, and doing I/O.
Waiting time. The CPU scheduling algorithm does not affect the amount of the time during which a process executes or does I/O; it affects only the amount of time that a process spends waiting in the ready queue. Waiting time is the sum of periods spend waiting in the ready queue.
Response time. In an interactive system, turnaround time may not be the best criterion. Often, a process can produce some output fairly early and can continue computing new results while previous results are being output to the user. Thus, another measure is the time from the submission of a request until the first response is produced. This measure, called response time, is the time it takes to start responding, not the time it takes to output the response. The turnaround time is generally limited by the speed of the output device.
It is desirable to maximize CPU utilization and throughput and to minimize turnaround time, waiting time, and response time. In most cases, we optimize the average measure. However, under some circumstances, it is desirable to optimize the minimum or maximum values rather than the average. For example, to guarantee that all users get good service, we may want to minimize the maximum response time. Investigators have suggested that, for interactive systems, it is more important to minimize the variance in the response time than to minimize the average response time. A system with reasonable and predictable response time may be considered more desirable than a system that is faster on the average but is highly variable. However, little work has been done on CPU-scheduling algorithms that minimize variance.
Refference : http://en.wikipedia.org/wiki/Scheduling_(computing)
The scheduler is concerned mainly with:
CPU utilization - to keep the CPU as busy as possible.
Throughput - number of processes that complete their execution per time unit.
Turnaround - total time between submission of a process and its completion.
Waiting time - amount of time a process has been waiting in the ready queue.
Response time - amount of time it takes from when a request was submitted until the first response is produced.
Fairness - Equal CPU time to each thread.
In real-time environments, such as mobile devices for automatic control in industry (for example robotics), the scheduler also must ensure that processes can meet deadlines; this is crucial for keeping the system stable. Scheduled tasks are sent to mobile devices and managed through an administrative back end.
Types of operating system schedulers
Operating systems may feature up to 3 distinct types of schedulers: a long-term scheduler (also known as an admission scheduler or high-level scheduler), a mid-term or medium-term scheduler and a short-term scheduler (also known as a dispatcher). The names suggest the relative frequency with which these functions are performed.
Long-term Scheduler
The long-term, or admission, scheduler decides which jobs or processes are to be admitted to the ready queue; that is, when an attempt is made to execute a program, its admission to the set of currently executing processes is either authorized or delayed by the long-term scheduler. Thus, this scheduler dictates what processes are to run on a system, and the degree of concurrency to be supported at any one time - ie: whether a high or low amount of processes are to be executed concurrently, and how the split between IO intensive and CPU intensive processes is to be handled. In modern OS's, this is used to make sure that real time processes get enough CPU time to finish their tasks. Without proper real time scheduling, modern GUI interfaces would seem sluggish. [Stallings, 399].1
Long-term scheduling is also important in large-scale systems such as batch processing systems, computer clusters, supercomputers and render farms. In these cases, special purpose job scheduler software is typically used to assist these functions, in addition to any underlying admission scheduling support in the operating system.
Mid-term Scheduler
The mid-term scheduler temporarily removes processes from main memory and places them on secondary memory (such as a disk drive) or vice versa. This is commonly referred to as "swapping out" or "swapping in" (also incorrectly as "paging out" or "paging in"). The mid-term scheduler may decide to swap out a process which has not been active for some time, or a process which has a low priority, or a process which is page faulting frequently, or a process which is taking up a large amount of memory in order to free up main memory for other processes, swapping the process back in later when more memory is available, or when the process has been unblocked and is no longer waiting for a resource. [Stallings, 396] [Stallings, 370]
In many systems today (those that support mapping virtual address space to secondary storage other than the swap file), the mid-term scheduler may actually perform the role of the long-term scheduler, by treating binaries as "swapped out processes" upon their execution. In this way, when a segment of the binary is required it can be swapped in on demand, or "lazy loaded".
Short-term Scheduler
The short-term scheduler (also known as the CPU scheduler) decides which of the ready, in-memory processes are to be executed (allocated a CPU) next following a clock interrupt, an IO interrupt, an operating system call or another form of signal. Thus the short-term scheduler makes scheduling decisions much more frequently than the long-term or mid-term schedulers - a scheduling decision will at a minimum have to be made after every time slice, and these are very short. This scheduler can be preemptive, implying that it is capable of forcibly removing processes from a CPU when it decides to allocate that CPU to another process, or non-preemptive (also known as "voluntary" or "co-operative"), in which case the scheduler is unable to "force" processes off the CPU.
Dispatcher
Another component involved in the CPU-scheduling function is the dispatcher. The dispatcher is the module that gives control of the CPU to the process selected by the short-term scheduler. This function involves the following:
Switching context
Switching to user mode
Jumping to the proper location in the user program to restart that program
The dispatcher should be as fast as possible, since it is invoked during every process switch. The time it takes for the dispatcher to stop one process and start another running is known as the dispatch latency.
Scheduling criteria
Different CPU scheduling algorithms have different properties, and the choice of a particular algorithm may favor one class of processes over another. In choosing which algorithm to use in a particular situation, we must consider the properties of the various algorithms. Many criteria have been suggested for comparing CPU scheduling algorithms. Which characteristics are used for comparison can make a substantial difference in which algorithm is judged to be best. The criteria include the following:
CPU Utilization. We want to keep the CPU as busy as possible.
Throughput. If the CPU is busy executing processes, then work is being done. One measure of work is the number of processes that are completed per time unit, called throughput. For long processes, this rate may be one process per hour; for short transactions, it may be 10 processes per second.
Turnaround time. From the point of view of a particular process, the important criterion is how long it takes to execute that process. The interval from the time of submission of a process to the time of completion is the turnaround time. Turnaround time is the sum of the periods spent waiting to get into memory, waiting in the ready queue, executing on the CPU, and doing I/O.
Waiting time. The CPU scheduling algorithm does not affect the amount of the time during which a process executes or does I/O; it affects only the amount of time that a process spends waiting in the ready queue. Waiting time is the sum of periods spend waiting in the ready queue.
Response time. In an interactive system, turnaround time may not be the best criterion. Often, a process can produce some output fairly early and can continue computing new results while previous results are being output to the user. Thus, another measure is the time from the submission of a request until the first response is produced. This measure, called response time, is the time it takes to start responding, not the time it takes to output the response. The turnaround time is generally limited by the speed of the output device.
It is desirable to maximize CPU utilization and throughput and to minimize turnaround time, waiting time, and response time. In most cases, we optimize the average measure. However, under some circumstances, it is desirable to optimize the minimum or maximum values rather than the average. For example, to guarantee that all users get good service, we may want to minimize the maximum response time. Investigators have suggested that, for interactive systems, it is more important to minimize the variance in the response time than to minimize the average response time. A system with reasonable and predictable response time may be considered more desirable than a system that is faster on the average but is highly variable. However, little work has been done on CPU-scheduling algorithms that minimize variance.
Refference : http://en.wikipedia.org/wiki/Scheduling_(computing)
MEMORY MANAGEMENT
Memory Management
Memory
Monoprogramming without Swapping or Paging
Monoprogramming with fixed partitions
Swapping
Virtual Memory
MEMORY
Memory is the electronic holding place for instructions and data that the computer's microprocessor can reach quickly. When the computer is in normal operation, its memory usually contains the main parts of the operating system and some or all of the application programs and related data that are being used. Memory is often used as a shorter synonym for random access memory (RAM). This kind of memory is located on one or more microchips that are physically close to the microprocessor in the computer. Most desktop and notebook computers sold today include at least 16 megabytes of RAM, and are upgradeable to include more. The more RAM you have, the less frequently the computer has to access instructions and data from the more slowly accessed hard disk form of storage.
Memory is sometimes distinguished from storage, or the physical medium that holds the much larger amounts of data that won't fit into RAM and may not be immediately needed there. Storage devices include hard disks, floppy disks, CD-ROM, and tape backup systems. The terms auxiliary storage, auxiliary memory, and secondary memory have also been used for this kind of data repository.
Additional kinds of integrated and quickly accessible memory are read-only memory (ROM), programmable ROM (PROMO), erasable programmable ROM (EPROM). These are used to keep special programs and data, such as the basic input/output system, that need to be in the computer all the time.
The memory is a resource that needs to be managed carefully. Most computers have a memory hierarchy, with a small amount of very fast, expensive, volatile cache memory, some number of megabytes of medium-speed, medium-price, volatile main memory (RAM), and hundreds of thousands of megabytes of slow, cheap, non-volatile disk storage. It is the job of the operating system to coordinate how these memories are used.
The part of the operating system that manages the memory hierarchy is the memory manager. It keeps track of parts of memory that are in use and those that are not in use, to allocate memory to processes when they need it and de-allocate it when they are done, and to manage swapping between main memory and disk when main memory is too small to hold all the processes.
Systems for managing memory can be divided into two categories: the system of moving processes back and forth between main memory and disk during execution (known as swapping and paging) and the process that does not do so (that is, no swapping and ping).
Monoprogramming without Swapping or Paging
The most simple memory management scheme is to run one program at a time, sharing the memory between that program and the operating system. As shown in the diagram bellow, there are three variations of this type. The operating system may be at the bottom of the memory in TAM (random access memory), as shown in the diagram 1, or it may be in ROM (read-only memory) at the top of the memory, as shown in diagram 2, or the device drivers may be at the top of the memory in a ROM and the rest of the system in RAM down bellow
With the system organised in this way, only one process at a time can be running. As soon as the user types a command, the operating system copies the request program from a disk to memory and executes it. When the process finishes, the operating system displays a prompt character and waits for a new command. When it receives the command, it loads a new program into memory overwriting the first one.
Monoprogramming with fixed partitions
It is often desirable to allow multiple processes to run at the same time, even on simple operating systems in which multiprogramming is sometimes used. On time-sharing systems, having multiple processes in memory at once means that when one process is blocked waiting for the I/O to finish, another one can use the CPU. This way, multiprogramming increases the CPU utilisation. It is however preferable to be able to run two or more programs at once even on personal computers.
Swapping
The process of organising memory into fixed partitions on batch system is simple compared to time sharing systems or graphically oriented personal computers. On batch systems, each job is loaded into a partition when it gets to the head of the queue. It stays in memory until it has finished. As long as enough jobs can be kept in memory to keep the CPU busy all the time, there is no reason to use anything more complicated. On time-sharing machines, sometimes there is not enough main memory to hold all the currently active processes, therefore excess processes must be kept on disk and brought in to run dynamically.
Swapping as an approach to memory management consists of bringing each process in its entirety, running it for a while, then putting it back on the disk. For details and illustrations, see OS design and implementation, A.S. Tanenbaum & A.S. Woodhull, Prentice Hall 1997, pg.310.
Virtual Memory
Another strategy for managing memory is the virtual memory, which allows programs to run even when they are only partially in main memory. The basic idea behind this strategy is that the combine size of the program, data, and stack may exceed the amount of physical memory available for it. The operating system keeps those parts of the program currently in use in main memory, and the rest on the disk.
Virtual memory can also work in a multiprogramming system, with bits and pieces pf many programs in memory at once. While a program is waiting for a part of itself to be brought in, it is waiting for I/O and cannot run, so the CPU can be given to another process, the same way as for any other multiprogramming system. Most virtual memory systems use a technique called paging.
Refference link: http://www.blogger.com/post-create.g?blogID=3983059508400695329
Memory
Monoprogramming without Swapping or Paging
Monoprogramming with fixed partitions
Swapping
Virtual Memory
MEMORY
Memory is the electronic holding place for instructions and data that the computer's microprocessor can reach quickly. When the computer is in normal operation, its memory usually contains the main parts of the operating system and some or all of the application programs and related data that are being used. Memory is often used as a shorter synonym for random access memory (RAM). This kind of memory is located on one or more microchips that are physically close to the microprocessor in the computer. Most desktop and notebook computers sold today include at least 16 megabytes of RAM, and are upgradeable to include more. The more RAM you have, the less frequently the computer has to access instructions and data from the more slowly accessed hard disk form of storage.
Memory is sometimes distinguished from storage, or the physical medium that holds the much larger amounts of data that won't fit into RAM and may not be immediately needed there. Storage devices include hard disks, floppy disks, CD-ROM, and tape backup systems. The terms auxiliary storage, auxiliary memory, and secondary memory have also been used for this kind of data repository.
Additional kinds of integrated and quickly accessible memory are read-only memory (ROM), programmable ROM (PROMO), erasable programmable ROM (EPROM). These are used to keep special programs and data, such as the basic input/output system, that need to be in the computer all the time.
The memory is a resource that needs to be managed carefully. Most computers have a memory hierarchy, with a small amount of very fast, expensive, volatile cache memory, some number of megabytes of medium-speed, medium-price, volatile main memory (RAM), and hundreds of thousands of megabytes of slow, cheap, non-volatile disk storage. It is the job of the operating system to coordinate how these memories are used.
The part of the operating system that manages the memory hierarchy is the memory manager. It keeps track of parts of memory that are in use and those that are not in use, to allocate memory to processes when they need it and de-allocate it when they are done, and to manage swapping between main memory and disk when main memory is too small to hold all the processes.
Systems for managing memory can be divided into two categories: the system of moving processes back and forth between main memory and disk during execution (known as swapping and paging) and the process that does not do so (that is, no swapping and ping).
Monoprogramming without Swapping or Paging
The most simple memory management scheme is to run one program at a time, sharing the memory between that program and the operating system. As shown in the diagram bellow, there are three variations of this type. The operating system may be at the bottom of the memory in TAM (random access memory), as shown in the diagram 1, or it may be in ROM (read-only memory) at the top of the memory, as shown in diagram 2, or the device drivers may be at the top of the memory in a ROM and the rest of the system in RAM down bellow
With the system organised in this way, only one process at a time can be running. As soon as the user types a command, the operating system copies the request program from a disk to memory and executes it. When the process finishes, the operating system displays a prompt character and waits for a new command. When it receives the command, it loads a new program into memory overwriting the first one.
Monoprogramming with fixed partitions
It is often desirable to allow multiple processes to run at the same time, even on simple operating systems in which multiprogramming is sometimes used. On time-sharing systems, having multiple processes in memory at once means that when one process is blocked waiting for the I/O to finish, another one can use the CPU. This way, multiprogramming increases the CPU utilisation. It is however preferable to be able to run two or more programs at once even on personal computers.
Swapping
The process of organising memory into fixed partitions on batch system is simple compared to time sharing systems or graphically oriented personal computers. On batch systems, each job is loaded into a partition when it gets to the head of the queue. It stays in memory until it has finished. As long as enough jobs can be kept in memory to keep the CPU busy all the time, there is no reason to use anything more complicated. On time-sharing machines, sometimes there is not enough main memory to hold all the currently active processes, therefore excess processes must be kept on disk and brought in to run dynamically.
Swapping as an approach to memory management consists of bringing each process in its entirety, running it for a while, then putting it back on the disk. For details and illustrations, see OS design and implementation, A.S. Tanenbaum & A.S. Woodhull, Prentice Hall 1997, pg.310.
Virtual Memory
Another strategy for managing memory is the virtual memory, which allows programs to run even when they are only partially in main memory. The basic idea behind this strategy is that the combine size of the program, data, and stack may exceed the amount of physical memory available for it. The operating system keeps those parts of the program currently in use in main memory, and the rest on the disk.
Virtual memory can also work in a multiprogramming system, with bits and pieces pf many programs in memory at once. While a program is waiting for a part of itself to be brought in, it is waiting for I/O and cannot run, so the CPU can be given to another process, the same way as for any other multiprogramming system. Most virtual memory systems use a technique called paging.
Refference link: http://www.blogger.com/post-create.g?blogID=3983059508400695329
Thursday, February 4, 2010
WINDOW NT SERVER INSTALLATION
WINDOWS NT 4.0 Server installation
There are several phases involved in NT server installation which are as follows:
Phase 0 Preparing for NT server installation
Phase 1 Gathering information about the computer on which you tend to install Windows NT
Phase2 Implementing Windows NT networking
Phase3 Finishing the set-up process
Now we will discuss these phases one by one to understand the complete installation process:
Phase0: Preparing for the installation of NT server
In the preparation phase of installation, NT copies sufficient files to run a limited version of NT server. Once this limited version of NT server is running the installation process is speeded up due to multi-tasking capabilities of Windows NT. During phase 0 the installation program tries to detect the hardware of your computer and more specifically it tries to detect the video adapter and the mass storage devices. After this information is found, the installation program will ask the installer on which partition the NT should be installed, which file system be used (FAT or NTFS), and the name of the directory in which the NT system files should be stored.
Phase 1: Gathering Information about the Computer selected for Installation
At this stage the information about your computer is collected by the installation program. During the phase you will be prompted to provide the following information:
(a) Name and organization: Here you have to select an appropriate and the name of your organization. It is necessary to give a user name, however the organization name is optional. This information is needed for licensing purpose only.
(b) Licensing Mode: There are two licensing modes, per server and per seat. In per server licensing mode, each server must be licensed for each concurrent connection. For example if you have 10 users and three servers and all ten users are needed to access all the three servers then each of the three servers must be licensed per server for 10 concurrent connection. In the per seat license each client is licensed at the client side and can access any number of servers in the network. If you have per seat license for 10 users then all the 10 clients can access all the three servers simultaneously and there is no need for having separate license for each server. So in a network with a multi-server environment the per client licensing is economical but for a single server small network per server licensing is advisable.
(c) Computer name: you have to give and appropriate name for computer. This name will be used for accessing the NT server computer from the network.
(d) Type of server: Here you have to specify whether your server to be installed will act as primary domain controller, Backup domain controller or a member server. If this is first server it is advisable to make it a PDC.
(e) Administrative password: you have to specify a password which will be used for logging into the system with administrative privileges.
(f) Emergency repair disk: you can create an emergency repair disk at this stage; it could be useful in fixing system problems later. ERD’s are machine specific and you have to create one for each NT machine.
(g) Optional components: Select the optional components here which you wish to install, the optional components include Accessibility options, Accessories, Communications, Games, Microsoft Exchange and Multimedia.
Phase 2: Implementing Windows NT networking
In this phase you have to supply the parameters which are related with the networking aspects of the server being installed. You have to supply answer related to following parameters:
1. Direct or Dial-in connection to the network: in this you have to specify the server to be installed which will be connected directly or through modem and telephone line. For installing NT server you will most likely connect it direct to the network.
2. Optional Installation of Internet information server: You can install the IIS if you wish to build an internet in your organization using your server else you may not choose this option.
3. Adapter and Protocols: Here you have to select the network card from the list of network cards which corresponds to the actual card installed in your system so that the installation program may install the appropriate driver for the same. In case the list does not contain the network card installed in your system then you have to choose the “Have Disk” option and then give the path of the line driver files on the floppy or CD-ROM or hard disk as the case may be( the floppy or the CD containing the LAN driver must have been supplied with the network card by the manufacturer). This process will load the appropriate LAN driver, then you have to select the appropriate protocol like TCP/IP, NetBEUI etc and see that the protocol is properly bound with the network. In case you select TCP/IP then you have to give a unique IP address and the sub-net mask for your computer in the network. (Every computer has a unique IP address consisting of four numerical fields of eight binary bits each. The Sub-net mask identifies the fields containing the network address part the node address part in the IP address.).
4. Additional Network Services: Select from such services as services for Macintosh or Gateway services for Netware. (You may not select them if you don’t want them presently, you can select the services at a later stage after installation also.).
5. Domain: Specify the name of the domain your computer should belong to. It is very important. In case your server is going to be a PDC then this is the domain your server will control. If this is the BDC or any other server then you have to give the name of the domain same as that of the PDC already existing. Please note that for the installation of a BDC the primary requirements is that the PDC must be on, running and connected to the network.
Phase 3
This is the last phase of installation program. The NT requires following information for completing the configuration:
(a) Date/Time and Time Zone: You have to give these parameters here for correct system time and time zone; else NT will pick these from the computer by default.
(b) Video Driver: After your video settings, you are asked to test your settings before they are saved. This helps in preventing from selecting wrong settings since the wrong settings may lead to unreadable display which is as good as non-functioning of the server.
After discussing the different phases of installation, now we can go on to detailed steps in installation, following which you can practically install the Windows NT server on any computer fulfilling the minimum hardware requirements as discussed earlier.
STEPS FOR INSTALLING WINDOWS NT 4.0 SERVER
(1) Boot your system to DOS or Windows 95/98.
(2) In case your computer is booted to DOS then ensure that CD driver is installed. Put the first CD in CD drive and from command prompt enter x:\i386\winnt where x is the drive letter for your CD drive. Then setup screen will appear and will ask the path where the Windows NT files are located. By default this will show the directory from where you run winnt. Press enter to continue. In case your computer is running under Windows 95/98 environment then you can give above mentioned path through Run option or can select through explorer.
(3) Next the winnt program will create three NT boot floppies( keep ready three of the high density blank floppies for this purpose) which will be used later to start the installation and provide the storage device drivers for your computer.
Be careful in nothing the order in which these floppies will be created, the order is NT server setup disk #3, setup disk #2 and setup boot up disk #1.
(4) After the floppies have been created, the NT server setup boot disk is already in the floppy drive and all you need is just press enter to reboot the system. The computer will boot to windows NT setup screen. It may take some time to load the necessary setup files.
(5) The system will then prompt you for inserting setup disk #2, insert disk #2 and press enter. Now more files will be loaded and Windows NT kernel will load.
(6) Next screen will be welcome to setup screen. We can also do NT server installation without use of any floppy. For this in step no. 2 when the setup screen appears we have to give /b option with winnt program (for example x:\i386\winnt /b) and then installation program will proceed without asking for any diskettes.
(7) NT will now attempt to detect your mass storage device. Press enter and continue.
(8) You will then be prompted for inserting diskette#3, insert this floppy and press enter.
(9) Next the installation will display a list of mass storage devices detected in the system (for a SCSII device only controller is listed). If you find this list to be correct, press enter. In case the list is not correct choose S and provide the driver for your mass storage device actually present but not listed. At this point the NT supported file system FAT and NTFS and the appropriate device driver for your computer will be installed.
(10) Next the license agreement screen will appear. In order to read the agreement press page down until you have read the agreement. Press f8 to accept the terms and conditions of the agreement. (if you don’t agree, installation will not take place).
(11) Then the installation program will display a list of hardware and software components detected on your computer. If this list is correct press enter.
(12) Next the system will ask you, on which drive you want the NT systems files to be loaded. (As an example choose c: partition and press enter).
(13) The next screen will ask you how to partition your drive. Select the option “leave your current files system intact” and press enter.
(14) Next give the path where your NT server will be installed, \winnt is the default, you may accept it and press enter.
(15) The NT server setup screen will now display a notice that setup program will now check your hard disks for corruption, press enter to continue. Some more files will be copied which may take few minutes.
(16) After the completion of file copying process you will be prompted for restarting your system. Remove any floppy from the floppy drive and press enter. The computer will restart and NT server will load. While the NT is loading the CHKDSK utility will run and automatically check the disk partations.
(17) Next the windows NT setup screen will appear, click next and this will start the phase one. (gathering information about your computer) of installation.
(18) Next you will be prompted to type in the registration CO-key. Type in this and click next.
(19) Next you will be prompted to type in the registration CD-key. Type in this and click next.
(20) Next screen is for selecting the licensing mode. Choose per server license for 10 users and click next.
(21) Next you have to type in the name of your computer and click next.
(22) Next you will be prompted for entering your server type out of primary domain controller, Backup domain controller or standalone server. If this is first server than select PDC, if it is second or any subsequent server in the selected domain and you want this server to replicate the user database with PDC so as to participate in user login authentication then select the server type as BDC. If you don’t want the database replication and the don’t want server to participate in login authentication then choose standalone server, in such a case your server will act like an application server or file server only.
(23) Next you will be prompted for giving administrator password. Type some suitable password and then retype the same as password. The password length should not exceed 14 characters.
(24) Next you will be prompted for creating the emergency repair disk. Insert a high density blank floppy in the floppy drive and choose the option yes.
(25) Next you will be asked the components which you want to install, accept the default choice and click next.
(26) Now the next installation phase(phase 2- Installing NT networking) appears. Choose and click next.
(27) The installation program will ask you how this computer will participate in the network, select “wired to the network”.
(28) Next the NT server installation program will ask you whether you want to install internet information server (IIS), in case you don’t want to set up intranet at this stage, deselect the choice by un-checking the box (you can install IIS later on at any time whenever you need it). Click next to continue.
(29) Next the installation program searches for your network adapter card. Click start search to begin the search. After your network card is found click next.
(30) Next the network protocol screen will appear, leave the default selection of TCP/IP and NWlink IPX/SPX compatible transport and click next.
(31) Next the network services screen will appear. Keep the default services, RPC configuration, NetBios interface, workstation and server. Click next.
(32) Click next to install your network components.
(33) Now the network card screen will appear. Check the hardware configuration or your card as per the one displayed on this screen, if it is ok, click next, else modify the options as required and then click continue.
(34) In the next stage you will be required to give the configuration detail of the protocols configure TCP/IP. You will get the following messages:- If there is a DHCP server you can find out from your system administrator. In case DHCP is not being used or you don’t want the IP addresses to be assigned automatically then in response to “Do you wish to use DHCP?”, choose No. the installation program will then copy files relating to selected network components.
(35) Next the IP address configuration screen will appear. Click the “specify an IP address option. As an example you can choose and type IP address, subnet mask and default gateway as follows:
• IP address 140.130.120.01
• Subnet Mask 255.255.00.00
• Default gateway leave blank
Click ok
(36) Next, the network binding screen will appear, keep all the default settings and click next.
(37) Then you will be prompted to click next to start the network.
(38) Windows NT set program will now ask you to enter your computer name and domain name, type in these two names of your choice and click next. The system will take few minutes to check for duplicate names.
(39) Now beings the third and installation program will see the finishing setup screen. Click finish and the installation program will complete some configuration information based on options selected by you earlier.
(40) The next screen will prompt you for date/time properties. NT picks up the date and time from your computer’s CMOS information. The time zone will default to Greenwich mean time, therefore select the appropriate settings for your time zone. Click close.
(41) Now NT will detect your video adapter. If the correct video adapter appears, choose ok. If the correct video adapter does not appear, you can customize it after completing the NT installation by going to control panel and selecting “Display”.
(42) You can test your display for the correct settings by selecting the test button and clicking OK and test your video driver, this will take around five seconds, NT will then ask “Did you see the Test bit map properly? If the display was correct select yes and click ok to save your settings. Click ok again to close the display settings window.
(43) NT will now complete copying the windows NT system files. When the file copying is complete, you will be prompted to insert a floppy and click ok. This will become your emergency repair disk. Finally remove any floppy and reboot your system. This is end of installation.
Wednesday, February 3, 2010
Features of Windows XP
1. Inbuilt drivers support for devices like Key board, mouse and Pen drives like peripherials.
2.Dramatically reduced reboot scenarios
3.Windows Firewall
4.Windows Security Center
5.Search
UPDATED PORTION OF BLOG
Information about WINDOW XP
In October 2001, Windows XP was released as an update to Windows 2000 desktop operating system and also as a replacement for Windows 95/98. In Windows XP, there are numerous features which have been added to automatically repair problems in applications and the operating system itself.
Windows XP is a multi user operating system which supports simultaneous access through distributed services or through multiple instances of GUI via the windows terminal server. The desktop versions of terminal server multiplex the keyboard, mouse and monitor between virtual terminal sessions for each logged in user. This feature, called fast user switching allows of a PC without having to log on and off the system.
Windows XP uses a client server architecture to implement multiple operating system personalities. It is the first version of windows to ship a 64-bit version.
There are 2 desktop versions of windows XP.
Windows XP professional is the premium desktop system for power user at work and at home. Windows XP personal provides reliability and ease of use for home users migrating from windows 95/98.
Advantages of Windows-XP
1) Security- Windows XP has a high level of protection from defective software and malicious attacks.
2) Reliability- Windows XP is the most reliable and stable OS.
3) Compatibility- Windows XP has introduced a new compatibility layer that falls between application and the Win.32 APIs.
4) Performance- Windows XP has a very high performance on desktop systems, which are largely constrained by I/O performance, Server systems (where CPU is often the bottleneck), and large multi threaded and multi processor environments (where locking and cache line management are key to scalability).
5) Extensibility- Windows XP has the capacity to keep up with advances in computing technologies.
6) Portability- Windows XP has the capability to be moved from one hardware architecture to another with relatively small changes.
7) International support- Windows XP is designed for international and multinational use. It provides us support for different locales via the national language support (NLS) API.
Faster boot and logon
1. The ability to boot in 30 seconds was a design goal for Windows XP, and Microsoft's developers made efforts to streamline the system as much as possible
2. Reduced reboot while installing new software in the windows XP
3. Presence of driver support for the drivers of keyboard, mouse and USB pen drive etc.
4. Autoplay system for inserted CD and Pen drivers
System administration improvements
Remote Desktop
5. Users can log into Windows XP Professional remotely through the Remote Desktop service. It is built on Terminal Services technology (RDP), and is similar to "Remote Assistance", but allows remote users to access local resources such as printers. Remote Desktop clients for earlier versions of Windows, Windows 95, Windows 98 and 98 Second Edition, Windows Me, Windows NT 4.0, or Windows 2000 have been made available by Microsoft
Fast user switching
6. Fast user switching allows another user to log in and use the system without having to log out the previous user and quit his or her applications. Previously (on both Windows ME and Windows 2000) only one user at a time could be logged in (except through Terminal Services), which was a serious drawback to multi-user activity. Fast User Switching, like Terminal Services, requires more system resources than having only a single user logged in at a time and although more than one user can be logged in, only one user can be actively using their account at a time.
Remote Assistance
7. Remote Assistance allows a Windows XP user to temporarily take over a remote Windows XP computer over a network or the Internet to resolve issues.
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