1 Windows 2000 Product family (Week 3, Monday 1/23/2006) © Abdou Illia, Spring 2006

2 Learning Objective Understand basic functions of OS Describe features of Windows 2000 Detail differences between Windows 2000 product family members

3 Operating Systems? Program initially loaded into computer memory Program that manages hardware & software resources:  Disks, memory, processors, application programs, etc. Key functions: Ensures that each application gets necessary resources Handles Input/Output operations Provides resource security (directory & file security, users profiles & rights)

4 Operating Systems? System software routines that sits between application programs and hardware to provide: Interface function Key support services User Application program Operating system Hardware Interfaces User communicates w/App. Prg. App. Prg communicates w/OS OS communicates w/Hardware All App. Prg access Hardware through OS according to rules imposed by OS Examples of support services: -Communications w/peripheral devices -Launching a program -Copying a file -Creating a directory -Opening a file

5 OS: Primary components User interface (shell) File management Device management Processor (or process) management Memory management Communication services Shell Provides mechanism for user and App. Prg to communicates w/OS and request OS support File management Allows the user to create, delete, modify, and manipulate files. Device management Controls communications w/peripheral devices Processor management Manages processor’s time Memory management Manages system’s memory Communication services Manages comm. Between OS layers and intercomputer communications.

6 OS at work Shell File management Device management Hardware Operating system’s layers Open Application program layer Steps for opening a file 1. User select File/Open from menu 2. App. Prg. calls the Open routine in the OS’s Shell 3. Shell passes the Open request to File management layer 4. File management layer determines where the requested file is located 5. If file on local computer, request is passed to Device management layer 6. Device management communicates with Hardware layer. Line command interface Graphical User interface Voice- activated interface Other OS layers Operating System User interface layer

7 Windows 2000 Family Workstation A Workstation B Workstation C Server A family of Operating Systems from Microsoft:  Windows 2000 Professional  Windows 2000 Server  Windows 2000 Advanced Server  Windows 2000 DataCenter

8 Features in Windows 2000 Active Directory (AD) services Enhanced security (using Kerberos version 5) Encrypting file system (EFS) Fault-tolerance (disk, configuration errors recovery, etc.) Clustering support Load balancing support FAT32, NTFS, CDFS, UDF support

9 Difference between Win 2000 family members Common OS functions No Disk Fault- tolerance Good for managing a network with a few computers in a Workgroup Disk Fault-Tolerance Active Directory Clustering Network Load-Balancing Workstation OS Network Operating systems

10 Disk fault tolerance Fault tolerance achieved through disk redundancy Disk redundancy can be accomplished:  by installing backup disk  Through Software RAID (Redundant Array of Independent Disks)  by installing RAID drives (Hardware RAID) RAID’s basic idea is  To mirror a disk (i.e. to have a disk and its identical image) or  To spread (or strip) data across many disks Server’s capability to continue functioning in case of disk failure RAID Controller Server Disk1 Disk3 Disk1

11 RAID RAID 0 Strips data across multiple disk No redundancy Advantage: Fast data access through multiple reads Disadvantage: Loosing one disk results in loosing data on all disks RAID 1 Doesn’t strip data across many disk Mirrors data between two disks Data kept synchronized between two disks Advantage: Fault-tolerance, i.e. If one disk fails, the other continue working until failed disk can be replaced Disadvantage: Only half of available storage space is used. Note: RAID 1 is called Mirrored volumes in W2K Server implementation of RAID

12 RAID RAID 3 Spreads data across multiple disks and uses ECC bits for recovery purpose in case of problem ECC bits determined based on data stored on data disks If one data disk fails, disk controller automatically regenerates missing data Data spread across these disks Last disk contains ECC* data for disks 1-4 * Error Checking and Correcting Note: RAID 3 is called RAID-5 volumes in W2K Server implementation of RAID

13 W2K Disk-Fault tolerance C: G: Ftdisk.sys Data Mirrored volume Parity RAID-5 volume Disk 1Disk 2Disk 3

14 Directory Service Provides: Single login and Resource lookup.

15 Active Directory Central Database that store information about all Network resources Tools for performing central management of users, groups, security services, and network resources (create, find, add, remove, configure etc.) Central Database used for:  Resource lookup (Searching for specific resources)  User authentication (login)

16 Active Directory Individual resources are called objects Objects belong to a Classes Each Class has its own attributes & properties User accountsComputersPrintersDomains Object classes Object name Object unique Identifier Required attributes Optional attributes Parent relationship Username User’s full name Password Account description Remote access OK Username: John Full mane: Johnny Doe Passord: 12#$ms Description: Consultant in Sales depart.

17 Clustering Technique for providing uninterrupted service (even in case of hardware/software failure) Combining two or more servers into one virtual server Services installed on external storage Users connect to the virtual server ( in illustration) One of the clustered servers provides the service at a time

18 Load Balancing Load balancing = Distributing the load among multiple computers No External disk containing services to be provided Multiple independent servers configure to participate in the load balancing Same service with the same content on each server Users connect to the virtual server ( in illustration) Users’ requests are redirected to one server at a time so that the load is distributed among all the servers Webservice Virtual server

19 Windows 2000 Requirements Workstation A Workstation B Workstation C Server Windows 2000 Professional Minimum Requirement: - 32 MB of RAM MB of free hard drive space Maximum Hardware specifications: - Support up to 2 processors - Support up to 4 GB of RAM Windows 2000 Server Minimum Requirement: -128 MB of RAM MB of free hard drive space Maximum Hardware specifications: - Support up to 4 processors - Support up to 4 GB of RAM

20 Windows 2000 Requirements Workstation A Workstation B Workstation C Server Windows 2000 DataCenter Server Minimum Requirement: MB of RAM - 2 GB HD with 1 GB Maximum Hardware specifications: - Support up to 16 processors - Support up to 64 GB of RAM Windows 2000 Advanced Server Minimum Requirement: MB of RAM - 2 GB HD with 1 GB free Maximum Hardware specifications: - Support up to 8 processors - Support up to 8 GB of RAM

21 Summary Questions Which of the following is a Workstation OS? a)Windows XP Professional b)Windows 2000 Professional c)Windows 2000 DataCenter d)Windows Me T or F: All application programs access Hardware through OS according to rules imposed by OS? T or F: A user can communicate directly with the OS T or F: Disk-Fault tolerance can be accomplished through hardware RAID or through software RAID.

22 Summary Questions You are setting up a network for a company. The major concern of the company’s CEO is being able to provide a continuous database service to its 300 employees as well as a reliable web-based ordering service to its customers all around the world. a)What feature(s) found in Windows 2000 family products could help the company to provide uninterrupted database and ordering services? Explain. b)Which Microsoft Windows 2000 operating system will you use to implement the two services? Why? c)Using illustrations, show how each of the two services will work.

23 Summary Questions What are the differences between Windows 2000 family products in terms of the features they include?

24 I 2 O Architecture I 2 O = Intelligent Input/Output Moves some I/O processing activities from CPU to processors on peripherals designed for I 2 O architectures (e.g. Hard drives) One general device driver for all I 2 O- compliant devices Increased speed Win 2000 Kermel OS Service ModuleHardware Device Module I 2 O Adapter with processor

25 Disk Contention architecture Disk Contention: # of simultaneous Read/Write requests Could be handled through the design of disk storage Primary design issues:  Disk Access Time (≤10 ms)  Data Transfer Rate (in MBps)  Type of Disk Controller (IDE, SCSI, Fiber Channel) Disk Drive Disk Controller Server