Multi tasking is when the operating system seems to be executing two or more undertakings at the same clip. i. e. MS Word and MS Access. nevertheless these undertakings are non really running at the same time as they are really resident in memory processor is really exchanging between undertakings at a really high velocity. therefore each user sees their ain undertaking as holding precedence. One disadvantage can be that the more plans that are run by the user. the more memory that is required. Multi Tasking can be split into two classs. co-operative and preemptive.
Co-operative is when the procedure presently commanding the CPU must offer a balanced portion of the CPU to all other procedures. hence Co-operative. as all procedures must co-operate for it to work decently. Subsequently an MUOS will let two or more users a portion of the system resources at the same clip. The usage of the resources must be spread equally between the demands of the users so that a job with one user does non go a job between all users. Examples of co-operative multi tasking would be Windows 3x and Macintosh.
Preemptive is when the applications are forced to portion the CPU whether they want to or non and illustrations of this are Windows 95. NT and UNIX.
How print sharing operates?
NOS – A print waiter allows multiple users entree to a individual pressman. A print waiter will besides give you information on the usage of the pressman. All print occupations are sent to a Network Printer. controlled by the waiter. where they will wait in bend to be printed. For illustration. you can:
See how many people are utilizing the pressman ;
Set bounds to the use ;
Give higher precedence to some workstations. leting them to publish before others ;
See who is presently publishing or ;
See when your print occupation is coming up.
MUOS – The Multi-User Operating System Linux uses a printing system called LPD. which invariably runs as a background procedure and acts as a spooler for files when they are required to be printed. Spooling ( Coincident Peripheral Operations On-Line ) is where all input/output of non-shareable devices is redirected to an intermediate shareable device. This is done. for illustration to halt other procedures line uping for long periods of clip to entree a certain device. The most common signifier of spooling would be print spooling. where paperss are printed at the printer’s ain rate after being loaded into an intermediate shareable country ( buffer ) . ) is where all input/output of non-shareable devices is redirected to an intermediate shareable device. This is done. for illustration to halt other procedures line uping for long periods of clip to entree a certain device. The most common signifier of spooling would be print spooling. where paperss are printed at the printer’s ain rate after being loaded into an intermediate shareable country ( buffer ) .
System Failure and Robustness
On a MUOS. informations must be backed up on a regular footing. as if the waiter goes down so all cursed work or informations on the web is lost. It is hence necessary to do a difficult transcript of all important informations. It is besides of import to hold a recovery phonograph record made upon installing. However. on a Network Operating System there is a system failure so merely the cursed informations on the existent client is lost and non across the full Network. The clients will still be about to the full operational without the waiter itself.
A Multi-User Operating System tends to be a batch more robust than a Network Operating System. It is widely recognised that Windowss in peculiar is really unpredictable at times and is prone to fatal mistakes. This is non the instance with the likes of Unix or Linux.
Application. file sharing and file lockup
File sharing is a really of import portion of a Network Operating System. Users will continuously necessitate to entree and portion the same files across a web and giving them usernames and watchwords can make this. However if two or more users were to seek and entree the same file ( for illustration. a Word papers ) at the same clip and both users on the Network had read and write entree. so merely one user would be granted entree at a clip and the other would be denied. This construct is known as File Locking. This could be looked upon as a basic traffic system. if you like. where every bit shortly as one user has entree to a file so the ruddy visible radiation is switched on. Then. when the first user has finished with the peculiar file. the green visible radiation shows and the 2nd user is free to entree the information. In a Multi User Operating System. you would happen a different method known as NFS ( Network File System ) . This is a where the waiter or Network Administrator can command which users can hold which type of entree to different applications or files at specific times.
Architecture & A ; Clients
A Network Operating System uses a Graphical User Interface. as it is portion of the Microsoft Windows household. which are all GUI’s. This makes the Operating System much easier to utilize in many ways such as being more user friendly and easier to larn.
However a Multi-User Operating System like Unix for illustration would utilize a Command Line Interface. This has its good and bad points being that the user has greater degree of control over bids ; the System is more stable and does non utilize inordinate system resources. On the other manus. the users would hold to familiarize themselves with a batch of bids which can be clip devouring. Both have the Kernel as the bosom of the Operating System. This is the portion of the operating system that loads foremost. and it remains in chief memory and typically. is responsible for memory direction. I/O system direction. file system direction. procedure and undertaking direction and programming. and disk direction. The Kernel is basically the “nucleus” of the operating system that provides basic services for all other constituents of the operating system. For each procedure. the Kernel holds a procedure identifier. the user individuality and the size and location of the procedure. A Network Operating System and a Multi-User Operating System will usually run utilizing “Thick “and “Thin ” clients severally:
No difficult disc on client
Connected to a waiter
Applications run on waiter
Datas stored on waiter
Mouse. Video. Keyboard etc. through which you can entree server
Can back up sound. CD-ROM etc.
Client has ain difficult disc
Client has storage infinite
Client can hold ain applications stored
Basically the antonym of “Thin clients”
A Network Operating System can back up many 100s of clients across a Local Area Network as can a Multi User Operating System.
Protocols and Internetworking
In order for a Network Operating System to direct or have informations. the information must be broken down into packages by a method called a protocol. Windows NT uses the IPX/SPX. NetBEUI. and TCP/IP protocols for web communicating. Netware uses IPX/SPX. UNIX. Linux. and the Internet all use TCP/IP. While different protocols normally can non speak straight with each other. most Network Operating Software can understand more than one protocol. This besides adds the possibility of Internetworking for most Network runing Systems as they can pass on freely over different Networks unlike MUOS.
Both types of operating system ( NOS and MUOS ) have constitutional TCP/IP networking. for communications across all signifiers of webs. and between all signifiers of computing machines. Other Protocols and the several beds of the OSI theoretical accounts at which they operate are shown here: –
Application – Telnet. HTML
Presentation – SMB. NCP
Session – NETBIOS ( NETBEUI )
Transport – TCP
Network – IP. TCP/IP. IPX/SPX
Data Link – Ethernet
Physical – Radio
Multi User Operating Systems are far more scalable because they can run on literally every hardware platform. from the slowest hardware to the world’s fastest. Additionally. most UNIX runing systems support more than one processor. so a machine configured with 4 processors can back up many more users than a machine with one processor of the same type.
Security steps are really of import on any Operating System. On a Network runing System such as Win 2000 waiter it would be reasonably easy to put in some kind of security package ( Firewall ) such as one of the Norton Internet Security bundles. Anti-virus package is besides readily available and really widely used. With a Multi-User Operating System such as Unix. there are a figure of security tools available to download as Freeware that perform a huge array of different undertakings associating to security.
Hardware demands: the Typical Hardware demands for put ining two different Operating Systems ( Linux and Windowss 2000 waiter ) are shown here below ( minimal and recommended ) :
MUOS ( Linux )
200 MHZ Processor required
32MB Random-access memory
650MB Hard Drive
Compact disc read-only memory
NOS ( Windows 2000 Server )
Pentium compatible 133MHZ or faster
128MB Random-access memory
2GB Hard Drive
Pentium II 200MHZ
256 MB RAM
9GB Hard Drive
Financially. Multi-User a Operating System would be much more feasible than a Network Operating System due to the fact that the MUOS can utilize dense Terminals. which fundamentally means that the bulk of the hardware and more significantly package is on the existent waiter i. e. the clients ( workstations ) have merely the indispensable constituents needed to run. These would include Keyboard. Mouse. proctor etc. nevertheless in the event of holding a really big Network this could in consequence terminal up every bit every bit dearly-won as a Network Operating System.
Role of Network Administrator
The function of a web decision maker in big companies and confer withing houses may be merely pull offing web waiters. adding users. and adding pressmans. However. most web decision makers besides do some desktop support every bit good as commanding web references. protocols used. and the web interfaces because these are all evidently web constituents. The web decision maker will besides command routing. name declaration. and assignment of TCP and UDP socket Numberss because. once more. these are all reasonably clearly web specific constituents. In little companies. daily web disposal is frequently non a full clip occupation and is assigned as a parttime undertaking to person in the office. To trouble-shoot a web you must understand things. such as: how single PCs work. general networking constructs. and merchandise specific characteristics.
A web decision maker is a director: non of people but of computing resources. A web decision maker is making and pull offing user histories. installation and keeping print services. guaranting that the web is running swimmingly and that the computing machines are running expeditiously. keeping the unity of the web. managing user ailments. and so forth. Users would be allowed entree to system resources by agencies of a user history. which would be set up and so users would be allocated a username and watchword ( s ) . This would let the Network Administrator to put different security degrees for different clients and users. For illustration. within a company or Business. you would hold different degrees of entree for different degrees of staff members with direction holding entree to more resources and informations than possibly an office junior etc.
A web decision maker should be able to pull off resources by making the followers:
Making. managing and utilizing Windows 2000 shared booklets
Using the Distributed File System to supply easy entree to web resources
Using the Windows 2000 events logs to supervise system and application activities
Using the Task Manager to detect and supervise resources
Using the System Monitor in the Performance tool to optimise public presentation
Using security policies to protect informations and system unity
Using scrutinizing to track security events
The Network Administrator is besides responsible for budgeting determinations sing the Network itself. This would affect really closely supervising each and every client. doing determinations on whether new hardware or package is required and when. Any Firewalls or Antivirus package would besides hold to be updated continuously.
hypertext transfer protocol: //www. North. ecasd. k12. Wisconsin. us/Departments/TCS/Web % 20Pages/Powerpoints/IT % 20Essentials % 202 % 20NOS % 20chpt % 206 % 203-03. ppt
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hypertext transfer protocol: //www. devdaily. com/unix/edu/UnixSysAdmin/node2. shtml
hypertext transfer protocol: //www. linksys. com/edu/nos. asp
hypertext transfer protocol: //www-personal. umd. umich. edu/~salmadra/common. htm
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hypertext transfer protocol: //www. cert. org/tech_tips/unix_security_checklist2. 0. hypertext markup language
hypertext transfer protocol: //www. cert. org/tech_tips/usc20_full. html # A13
Dick. David ( 2002 ) The P. C. Support Handbook. Kirkintilloch: Dumbreck Publication