info 320 server technology i n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
INFO 320 Server Technology I PowerPoint Presentation
Download Presentation
INFO 320 Server Technology I

Loading in 2 Seconds...

play fullscreen
1 / 34

INFO 320 Server Technology I - PowerPoint PPT Presentation


  • 109 Views
  • Uploaded on

INFO 320 Server Technology I. Week 1 Server operating system and hardware concepts. Overview. This course covers basic operating system (OS), server, and architecture concepts Here we’ll mainly focus on server operating systems, though much of their functionality is done by any OS.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'INFO 320 Server Technology I' - zlhna


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
info 320 server technology i

INFO 320Server Technology I

Week 1

Server operating system and hardware concepts

INFO 320 week 1

overview
Overview

This course covers basic operating system (OS), server, and architecture concepts

Here we’ll mainly focus on server operating systems, though much of their functionality is done by any OS

INFO 320 week 1

linux and unix
Linux and UNIX

Much of our emphasis will be on Linux and UNIX, since that’s the OS in most servers

The labs will use the Ubuntu distribution of Linux

What other kinds of server operating system are there?

What kind of operating systems are there, other than server OS’s?

INFO 320 week 1

what does an os do
What does an OS do?

An OS lets applications use server hardware

User

CLI or GUI

Application

API or system calls

Interrupts ordevice drivers

OS

Hardware

INFO 320 week 1

server hardware
Server hardware

So the point of an operating system is to be able to access hardware

What hardware does a server have?

What hardware characteristics do we care about from the selection or management perspective?

INFO 320 week 1

possible traits of an os
Possible traits of an OS

What are these terms?

Multi-user OS

Multiprocessing OS

Multitasking OS

Which of these can a server OS perform?

INFO 320 week 1

resources and sharing
Resources and Sharing
  • One way to look at a computer is as a set of resources
    • The CPU of a computer is a resource
    • The memory of a computer is a resource
    • The keyboard of a computer is a resource
    • The hard disk drive of a computer is a resource

INFO 320 week 1

why consider this way of looking at computers
Why consider this way of looking at computers?
  • Since the CPU of a computer operates at extremely high speeds, and since there is a speed differential between the CPU and other resources
  • When the CPU is waiting for another resource, it is essentially wasting time – if the only thing that it is doing is waiting

INFO 320 week 1

resources and sharing1
Resources and sharing
  • On the other hand if we can have the CPU do something else while it is waiting for a resource we can make better use of the CPU resource – we won’t waste as much of the capability of the resource
  • If we were to do this then we would be able to share the CPU resource among more than a single task
  • The term multitasking derives from this approach
  • Multitasking allows us to share computer resources
  • The sharing of one or more computer resources is controlled by scheduling

INFO 320 week 1

what does an os do1
What does an OS do?

Process management

Interrupts

Memory management

Storage management and disk access

Device drivers

Networking

Security

INFO 320 week 1

process management
Process management

Executing a process means creation of a process by the OS

A task is a collection of processes

The OS kernel creates a process by assigning it memory, and defining its priority

Then the program is loaded into memory, and executed by the (a?) CPU

INFO 320 week 1

process management1
Process management
  • In order to multitask, we need a mechanism to share all of the computer resources among the tasks that require it
  • The sharing requires a manager, called the kernel of the operating system

INFO 320 week 1

process management2
Process management

A process can be in three possible states

executing

Needs data

Is preempted

Gets data and CPU

Gets CPU

Gets data

waiting

ready

Needs data

INFO 320 week 1

process management3
Process management

Having multiple processes leads to the need for scheduling

Processes are assigned priorities

CPU time goes to highest-priority process that is ready

INFO 320 week 1

interrupts
Interrupts

An interrupt is a signal informing a program that an event has occurred

Interrupts are handled by the OS kernel, and may come from software or hardware

When an interrupt is received, the hardware suspends whatever program is running, and might take other actions

INFO 320 week 1

interrupts1
Interrupts

Hardware interrupts might include

Keystrokes

Inputs from other devices (mouse, printer, etc.)

Software interrupts include

A program needs to get to hardware (save a file)

Program needs more memory

INFO 320 week 1

memory management
Memory management

The OS kernel includes a memory management unit (MMU)

This makes it possible for several processes to share main memory

An application deals with logical memory addresses

The MMU deals with physical addresses

INFO 320 week 1

memory management1
Memory management

The kernel protects memory usage via swapping, paging, and segmentation

Swapping is when a process is temporarily moved to a backing storage location

The process is swapped out to storage, then back in

INFO 320 week 1

memory management2
Memory management

Paging manages physical memory space

Physical memory is divided into frames

Logical memory is divided into pages

Frames and pages have the same size, defined by the hardware involved

INFO 320 week 1

memory management3
Memory management

Segmentation is the mapping of logical address space for each process into segments

A segment table keeps track of each segment’s name, length, and the offset to find its physical memory location

Attempts to address other memory locations results in a segmentation fault interrupt

INFO 320 week 1

storage management
Storage management

All OS’s need a way to access stored data

Data is stored on devices using files and directories

Files are structured to allow fast access, improve reliability, and make efficient use of space

A file system is a method for storing and organizing data

INFO 320 week 1

storage management1
Storage management

OS activities include

Create and delete files and directories

Manipulate files and directories

Back up files onto storage media

UNIX and Linux support Virtual File Systems (VFS)

Allows interoperability with Mac and Windows, transparent to the user

INFO 320 week 1

storage management2
Storage management

File system examples

Solaris uses Unix file system

Linux uses extended file system (ext4)

MS-DOS used File Allocation Tables (FAT)

Mac OS used Hierarchical File System (HFS), and now supports Unix file systems

Windows NT/XP/Vista/7 use NT File System (NTFS)

INFO 320 week 1

device drivers
Device drivers

Device drivers allow software to communicate with specific kinds of hardware

Each OS has drivers for each device

Hardware manufacturers develop drivers

INFO 320 week 1

networking
Networking

Most OS’s support various networking protocols, both open source and proprietary formats

What networking protocols might you expect to be supported?

Various network architectures are also supported

Client/server, peer to peer, hybrid

INFO 320 week 1

security
Security

Within a network, the server OS is a critical security component

Controls access to processes, and data

Networking aspect also affects external security threats

Denial of service, worms, Trojan horses, etc.

INFO 320 week 1

security1
Security

Within a network, security is controlled by user and group identification

User has a user ID

Belongs to a group which has a group ID

Anyone else is considered ‘other’ = outside your group

INFO 320 week 1

security2
Security

Each file and directory can be controlled to have different privileges for user, group, and other (u-g-o)

The allowed privileges are

read

write (includes create, modify, or delete)

execute (application or script)

INFO 320 week 1

os examples
OS Examples

Microsoft Windows

Huge worldwide market share

Windows NT is the basis for Windows 2000, XP, Vista, and 7, plus Windows Server 2003 and 2008

INFO 320 week 1

os examples1
OS Examples

Unix

Now over 40 years old, the longest lived family of operating systems

Mainly used in business and academia

Sun  Solaris (was SunOS)

HP  HP/UX

IBM  AIX

SGI  IRIX (obsolete)

NeXT (obsolete, but basis for Mac OS X)

INFO 320 week 1

os examples2
OS Examples

Unix-like variants

Linux

FreeBSD

openSolaris

INFO 320 week 1

os examples3
OS Examples

Macintosh

System 1-9

OS X and OS X Server (based on BSD Unix)

Mainframe OS’s

OS/400 (IBM AS/400)

DEC VMS and openVMS

OS/360 (IBM mainframes e.g. RS/6000)

INFO 320 week 1

os examples4
OS Examples

Google Chrome

Based on Linux

All apps other than the OS kernel will be delivered in a web browser

Apps and data are in the cloud, not locally

INFO 320 week 1

os examples5
OS Examples

Real time OS’s

Typically used when time-predictable response to many inputs are needed

Video or audio processing, system control software, many complex hardware/software systems

There are real time versions of Linux, and many other custom OS’s

INFO 320 week 1