Lesson 1: Intro to OS Flashcards
program (software) that acts as an INTERMEDIARY (INTERFACE between a user of a computer and the computer hardware
Operating System
MANAGES the computer hardware and PROVIDES A BASIS for application programs
Operating System
more common to describe an operating system
Kernel
one program RUNNING AT ALL TIMES on the computer
Kernel
Operating System Goals (CCSE)
CONTROL/execute application programs
Make the computer system CONVENIENT to use
Make SOLVING user problems easier
Use the computer hardware in an EFFICIENT manner
Types of Operating System (BTNDR aka bartender)
Batch Operating System
Time-Sharing Operating System
Network Operating System
Distributed Operating System
Realtime Operating System
[Types of OS] NO DIRECT INTERACTION between the user and the computer, operator SORTS similar jobs into batches
Batch OS
Examples of Batch OS
Payroll System
Bank Statements
Advantages of Batch Operating Systems (TWIS)
TIME: processors know how long the job would be when it is in queue
WORK: easy to manage large work repeatedly
IDLE: idle time is very less
SHARE: multiple users can share
Disadvantages of Batch Operating Systems (CODW)
COSTLY: sometimes costly
OPERATOR: computer operators should be well known
DEBUG: hard to debug
WAIT: other jobs will have to wait for an unknown time if any job fails
[Types of OS] considered as extension of multiprogramming systems also known as MULTITASKING SYSTEMS
Time-Sharing OS
[Types of OS] prime focus is onminimizing the response time
Time-Sharing OS
Examples of Time-Sharing OS
Multics
Unix
Advantages of Time-Sharing OS (ODI)
OPPORTUNITY: each task gets an equal opportunity
DUPLICATION: less chances of duplication of software
IDLE TIME: CPU idle time can be reduced
Disadvantages of Time-Sharing OS (RSD)
RELIABILITY: Reliability problem
SECURITY: One must have to take care of security and integrity of user programs and data
DATA COMMNICATION: Data communication problem
[Types of OS] various autonomous INTERCONNECTED computers communicate each other using a SHARED communication network
Distributed OS
[Types of OS] independent systems possess own memory unit and CPU, referred as LOOSELY COUPLED SYSTEMS or DISTRIBUTED SYSTEMS
Distributed OS
[Types of OS] system’s processors differ in size and function
Distributed OS
Examples of Distributed OS
LOCUS
MICROS
Advantages of Distributed OS (CIDLSD)
COMPUTATION: computation is highly fast and durable
INDEPENDENT: failure of one will not affect the other network communication, as all systems are independent from each other
DATA EXCHANGE: email increases the data exchange speed
LOAD: load on host computer reduces
SCALE: easily scalable as many systems can be easily added to the network
DELAY: delay in data processing reduces
Disadvantages of Distributed Operating System (LAN)
LANGUAGE: the language which are used are not well defined yet
AVAILABILITY: not readily available as they are very expensive, highly complex underlying software, and not understood well yet
NETWORK: failure of the main network will stop the entire communication
[Types of OS] OSs that run on a server and provide the capability to manage data, users, groups, security, applications ang other networking functions known as TIGHTLY COUPLED SYSTEMS
Network OS
[Types of OS] allow SHARED ACCESS of files, printers, security, applications and other networking functions over a SMALL PRIVATE NETWORK
Network OS
[Types of OS] All the users are well aware of the underlying configuration, of all other users within the network, and their individual connects
Network OS
Examples of Network OS
Microsoft Windows Server 2003
Microsoft Windows Server 2008
UNIX
Linux
Mac OS X
Novell NetWare
BSD
Advantages of Network Operating System (clue: USSR)
UPGRADE: New technologies and hardware up-gradation are easily integrated to the system
STABLE: Highly stable centralized servers
SECURITY: Security concerns are handled through servers
REMOTE: Server access are possible remotely from different locations and types of systems
Disadvantages of Network Operating System (CDM)
COSTLY: Servers are costly
DEPENDANCE: User has to depend on central location for most operations
MAINTENANCE: Maintenance and updates are required regularly
[Types of OS] serves the real-time systems
Real-Time OS
time interval required to process and respond to inputs
Response Time
[Types of OS] used when there are time requirements are very strict
Real-Time OS
Examples of Real-Time OS
Scientific experiments
Medical imaging systems
Industrial control systems
Weapon systems
Robots
Air traffic control systems
Two Types of Real-Time OS (HS)
Hard Real-Time Systems
Soft Real-Time Systems
[Types of Real-Time OS] meant for the applications where time constraints are VERY STRICT and even the shortest possible delay is not acceptable, built for SAVING LIFE that are required to be readily available in case of any accident, VIRTUAL MEMORY is almost never found
Hard Real-Time Systems
[Types of Real-Time OS] applications where for time-constraint is less strict
Soft Real-Time Systems
Advantages of Real-Time Operating System (METFEM)
MAX CONSUMPTION: max utilization of devices and system, more output from all the resources
ERROR FREE: error free
TASK SHIFTING: time assigned for shifting tasks in these systems are very less
FOCUS ON APPLICATION: focus on running applications and less importance to applications which are in queue
EMBEDDED SYSTEM: can also be used in embedded systems
MEMORY ALLOCATION: memory allocation is best managed
Disadvantages of Real-Time Operating System (CHLDT /child tee/)
COMPLEX ALGORITHMS: algorithms are very complex and difficult for the designer to write on
HEAVY SYSTEM RESOURCES: sometimes the system resources are not so good, and they are expensive as well
LIMITED ASKS: very few tasks run at the same time and their concentration is very less on few applications to avoid errors
DEVICE DRIVER AND INTERRUPT SIGNALS: needs specific device drivers and interrupt signals to response earliest to interrupts
THREAD PRIORITY: not good to set thread priority as these systems are very less prone to switching tasks
Computer System Components (HOAU)
Hardware
Operating System
Application Programs
Users
[Computer System Components] provides basic computing resources
Hardware
[Computer System Components] controls and coordinates the use of the hardware among the various application programs for the various users
Operating System (OS)
[Computer System Components] define the ways in which the system resources are used to solve the computing problems of the users
Application Programs
[Computer System Components] includes people, machine or other computers
Users
Operating System Services (UPFICE)
User Interface
Program Execution
I/O Operations
File-System Manipulation
Communication
Error Detection
[Operating System Services] several forms of user interface (CBG)
Command-line Interface
Batch Interface
Graphical User Interface (GUI)
[Operating System Services, UI] uses text commands and methods for entering them such as typing commands with the use of keyboard in a specific format
Command-line Interface
[Operating System Services, UI] commands and directives are entered into files to control commands and execute those files
Batch Interface
[Operating System Services, UI] interface is a window system using a pointing device to direct I/O, choose from menus and making selections and a keyboard in entering text
Graphical User Interface (GUI)
[Operating System Services] system must be able to load a program into memory and to run that program and must be able to end its execution, whether normally or abnormally
Program Execution
[Operating System Services] must provide a means to do involving I/O
I/O Operations
[Operating System Services] programs need to read and write files and directories. The need to create and delete, search, and list file information
File-System Manipulation
[Operating System Services] a process needs to exchange information with another process occurring on the same or different computers
Communications
[Operating System Services] OS needs to detect and correct errors constantly which may occur in CPU and memory hardware, in I/O devices and in the user program
Error Detection
