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Chapter 1
Operating Systems Introduction
41
Computer Science
Undergraduate 3
03/05/2012

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Term
Operating System
Definition
  • A program that manages the computer hardware.
  • Basis for application programs.
  • Intermediatary between computer user and hardware.
  • Convience vs. Effeciency.
Term
Computer System Components
Definition
  • Hardware, Operating System, Application Programs, and the Users.
Term
Hardware
Definition
  • CPU, Memory, and I/O Devices.
  • Provides basic computing resources for the system.
Term
Application Programs
Definition
  • Browsers, word processors, etc
  • Defines ways in which hardware is sued to solve users computing problems.
  • OS controls proper use of hardware.
Term
Resource Utilization
Definition
  • How various hardware and software resources are shared.
Term
Mainframe
Definition
  • Multiple users access same computer through other terminals.
Term
Workstations / Servers
Definition
  • Workstation(s) connects to networks of other workstations and servers.
  • Dedicated resources, shared resources.
Term
Resource Allocator
Definition
  • Another name for Operating System.
  • An Operating System is the program most intimately involved with the hardware.
  • Operating system decides how to handle requests for resources.
Term
Control Program
Definition
  • Manages the execution of user programs to prevent errors and improper use of the computer.
  • Concerned with the operation and control of I/O devices.
Term
Kernel
Definition
  • One program running at all times on computer.
Term
Systems Programs
Definition
  • Associated with operating system, but not part of kernel.
Term
Application Programs
Definition
  • All programs not associated with operating of the system.
Term
Bootstrap Program
Definition
  • Initial Program to run.
  • Must know how to load the O.S. and start executing that system.
  • Locates and loads into memory the O.S. Kernel.
Term
Firmware
Definition
  • Stores Bootstrap.
  • ROM or EEPROM.
Term
Interrupt
Definition
  • Some event signalled by hardware or software.
  • Hardware can trigger interrupt at any time.
Term
System Call (Monitor Call)
Definition
  • Interrupt triggered by software.
Term
Interrupt Vector
Definition
  • Array of addresses.
  • Indexed by a unique device number given with the interrupt request, to provide the address of the interrupt service routine.
Term
SCSI
Definition
  • Controls seven or more devices.
Term
Device Driver
Definition
  • Used to understand device controller and presents uniform interface to the device to the rest of the Operating System.
  • Interrupt / Byte
Term
Direct Memory Access (DMA)
Definition
  • Used for reducing high overhead produced by buil data movement such as disk I/O.
  • Interrupt / Block
  • Transfers entire block from buffer to memory without CPU.
Term

Multiporcessor Systems

(Parallel Systems)

Definition
  • Two or more processors in close communication, sharing bus, and sometimes clock memory, and peripheral devices.
Term
Multiprocessor System Advantages
Definition
  • Increased Throughput
  • Economy of Scale
  • Increased Reliability
Term
Graceful Degradation
Definition
  • The ability to continue providing service proportional to the level of surviving hardware.
Term
Fault Tolerant
Definition
  • Can suffer a failure of any single component and still continue operation.
  • Requires a mechanism to allow the failure to be detected, diagnosed, and if possible, corrected.
Term
Asymmetric Multiprocessing
Definition
  • Each processor is assigned a specific task.
  • A multiple-processor system.
Term
Symmetric Multiprocessing (SMP)
Definition
  • Each processor performs all tasks within the operating system.  
  • All processors are peers; no master-slave relationship between processors.
  • A multiple-processor system.
Term
Blade Servers
Definition
  • Multiple processor boards, I/O boards, and networking board are placed in the same chassis.
  • Each blade-processor board boots independently and runs its own operating system.
  • In essence, these servers consist of multiple independent multiprocessor systems.
Term
Clustered System
Definition
  • Gather together multiple CPUs to accomplish computational work.
  • Differ from multiprocessor systems, however, in that they are composed of two or more individual systems -- or nodes -- joined together.
Term
High-Availability Service
Definition
  • Service will continue even if one or more systems in the cluster fail.
  • Obtained by adding a level of redundancy in the system.
Term
Asymmetric Clustering
Definition
  • One machine is in hot-standby mode while other is running the applications.
Term
Hot-Standby Mode
Definition
  • Monitors the active server.  If it fails, then hot-standby host becomes the active server.
Term
Symmetric Mode
Definition
  • Two or more hosts are running applications and are monitoring each other. 
  • Uses all hardware; More efficient.
  • Requires that one application be available to run.
Term
High-Performance Computing
Definition
  • Can supply significantly greater computational power than single-processor or even SMP systems.
  • Capable of running an application concurrently on all computers in the cluster.
  • Uses parallelization.
Term
Parallelization
Definition
  • Consists of dividing a program into separate components that run in parallel on individual computers in the cluster.
  • Once each computer node in the cluster has solved its portion of the problem, the results from all nodes are combined into a final solution.
Term
Distributed Lock Manager (DLM)
Definition
  • The supply of access control and locking to ensure that no conflicting operations occur.
Term
Storage-Area Networks (SANS)
Definition
  • Allow many systems to attach to a pool of storage.
  • Can assign the application to run on any host that is attached to the SAN.
Term
Multiprogramming
Definition
  • Increases CPU utilization by organizing jobs (code and data) so that the CPU always has one to execute.
Term
Job Pool
Definition
  • Where jobs are kept initially on the disk.
  • Consists of all processes residing on disk awaiting allocation of main memory.
  • Main memory is too small to accomodate all jobs.
Term

Time sharing

(or Multitasking)

Definition
  • A logical extension of multiprogramming.  
  • The CPU executes multiple jobs by switching among them.
  • Switches occur so frequently that the users can interact with each program while it is running.
Term

Interactive Computer System

(hands on)

Definition
  • Provides direct communication between the user and the system.
  • The user gives instruction to the operating system or to a program directly, using a input device such as a keyboard or a mouse, and waits for immediate results on an output devices.
  • The response time is kept short.
Term
Process
Definition
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