Resource Sharing Over a Network Guide to Operating Systems Third Edition.

Resource Sharing Over a Network

Guide to Operating Systems Third Edition

Guide to Operating Systems, Third Edition 2

Objectives

After reading this chapter and completing

the exercises you will be able to:

• Explain the principles behind sharing disks and

files on a network

• Set up accounts, groups, security, and disk and

file sharing on network server operating systems


Objectives (continued)

After reading this chapter and completing the exercises you will be able to:

• Set up disk and file sharing on client operating systems

• Set up printer sharing on server and client operating systems

• Discuss how network and Internet servers are used for vast information-sharing networks


• One of the first reasons for linking a workstation’s operating system onto a network

• NetWare was early on the scene to enable file sharing through a server

– by downloading a file from a file server

– by purchasing third-party software to create a special shared drive

Sharing Disks, Files and Printers


• Share entire applications over the network

– Download the entire executable

– Only one version needed on the server

• Mapping

– enables a client workstation to attach to the shared drive of another workstation or server

– drive letter assigned

Sharing Disks, Files and Printers (continued)


Sharing Disks, Files and Printers (continued)

• Mounted volume

– term used in UNIX/Linux and Mac OS X for a mapped drive


Securing Shared Resources

• Potential security risk for non-authorized users

to access a file or use a printer

• Operating systems discussed in this book offer

security measures


Sharing Disks and Files Through Server Network

Operating Systems• Examples of server network operating systems

that share disks and files over a network – Windows 2000 Server

– Windows Server 2003

– UNIX/Linux

– Mac OS X Server

– NetWare


Sharing Disks and Files Through Server Network

Operating Systems• Network administrator may establish security

– by assigning accounts, account passwords, groups, and access privileges


Windows 2000 Server and Windows Server 2003

• Uses accounts, groups, and permissions

• Steps involved include setting up the following:

– Groups – Account policies

– User accounts – Permissions

– Shared disk and folders



(continued)

• Use groups to manage resources and permissions– Local

– Domain local

– Global

– Universal



(continued)

• Groups are defined as security or distribution groups

• Security groups

– used to enable access to resources on a standalone server or in Active Directory

• Distribution groups

– used for e-mail or telephone



(continued)• Container object

– entity that is used to group together resources in a directory service

• Tree

– consists of one or more domains

• Forest

– houses one or more trees



(continued)• Universal group guidelines

– use global groups to hold user accounts as members

– use domain local groups to provide access to resources in a specific domain

– use universal groups to provide extensive access to resources

– manage user accounts access


Windows NT Server

• Trusted domain

– such as college.edu

– granted access to the resources in another domain such as research.college.edu

• Trusting domain

– research.college.edu allows access to its resources to college.edu



(continued)

• Before any accounts are created, it is wise to establish the account policies

• Three categories:– Password security

– Account Lockout

– Kerberos security



(continued)• Password security options:

– enforce password history

– maximum password age

– minimum password age

– minimum password length

– password complexity requirements

– password storage using reversible encryption



(continued)• Account lockout options:

– account lockout duration

– account lockout threshold

– reset account lockout count



(continued)

• Kerberos options:– enforce user logon restrictions

– maximum lifetime for a service ticket

– maximum lifetime for a user ticket

– maximum lifetime for a user ticket renewal

– maximum tolerance for a computer clock synchronization



(continued)

• Share

– an object given a name and made visible to network users

• Disk or folder - shared through its properties


Windows 2000 Server and Windows Server 2003 (continued)

• Share permissions:– Read

– Change

– Full Control



• Dialog box in Figure 9-6 has a caching button

• Caching

– enables you to set up a folder so that it can be accessed by a client, even when the client is not connected to the network

• Web sharing

– files available on a Web server for HTML or FTP access

– See Tables 9-2 and 9-3





(continued)



• Troubleshooting a security conflict:– review folder and share permissions

– take into account what happens when a folder or files are copied or moved

– inherited properties


UNIX and Linux

• User identification number (UID)– each user account in UNIX is associated with a UID

• Group identification number (GID)– users who have common access needs


UNIX and Linux (continued)

• The password file (/etc/passwd) contains :– user name

– encrypted password or a reference to the shadow file

– UID

– GID

– information about the user

– location of the user’s home directory

– which shell to use



• Shadow file (/etc/shadow) contains password restriction information :– minimum and the maximum number of days

between password changes

– Information on when last changed

– Warning information about password expiration

– Amount of time that the account can be inactive before access is prohibited



• Home directories

– areas on the server in which users store data

• Information about groups is typically stored in the /etc/group file



• Permissions are granted on the basis of

– ownership

– group membership

– other (or World)

– all (all is not used in every version of UNIX, but is included in Red Hat Enterprise Linux)

• Permissions are set up by using the chmod command

• Chmod has two different formats, symbolic and octal


NetWare• Novell NetWare server installation

– first task is to design a file structure

• Default directories:– SYSTEM

– PUBLIC

– LOGIN

– HOME

– APPS

– DATA


NetWare (continued)

• Net Administrator tasks:

– Set security on each directory, subdirectory, and on particular files

– Create an account and account password for each user

– Set up groups as a way to provide shortcuts for managing security


NetWare (continued)

• Search drive

– given drive letters such as S1 for the first drive, S2 for the second drive, and so on

• Difference between a mapped network drive and a mapped search drive

– NetWare can execute a file on a search drive, whether the file is in the main directory or in a subdirectory under the search drive


NetWare (continued)

• A login script is a file of commands associated with an account or a group of accounts


NetWare (continued)

• A user account can be set up in ConsoleOne using several kinds of restrictions:

– Requiring a password

– Setting a minimum password length

– Requiring that a password is changed within a specified interval of time

– The remainder are listed on page 453 of the textbook


NetWare (continued)• Administrator can grant rights to access

specific directories, subdirectories, and files

• The rights control the ability to:– Perform a directory listing

– Create a new directory, subdirectory, or file

– Read contents of a directory, subdirectory, or file

– Write to the contents of a file

– Refer to the list on page 454 of the textbook for the rest


NetWare (continued)

• Objects – such as user accounts, groups, printers, directories,

subdirectories, files, and other resources

• Novell Directory Services (NDS)

– stores information about objects

• Leaf objects

– store information about clients


Mac OS X Server• The Mac OS X Server is designed as a true server

– file sharing

– printer sharing

– managing network users and groups

– providing Web services

• Mac OS X Server

– can support up to several thousand users

– includes the Apache Web server software

– supports TCP/IP and AppleTalk


Mac OS X Server (continued)

• Included tools

– Server Admin

– Macintosh Manager

• Share points

– shared resources on a server


Mac OS X Server (continued)

• Logging of events can include:

– Login and Logout events

– Opened files

– Newly created files

– Newly created folders

– Deleted files and folders


Accessing and Sharing Disks and Files Through Client

Network Operating Systems

• Many operating systems

– include the ability to act as clients

– to map to disks and directories on servers


• Windows 2000 Professional

– Access a shared drive over the network

– Map the drive using My Network Places

• The steps for mapping a drive are shown on page 457

• Same process for Windows 2000 Server

Accessing and Sharing Resources in Windows 2000 Professional


Accessing and Sharing Resources in Windows XP

• Uses My Network Places to locate and map network drives

• Fastest way to access My Network Places is to use the steps on page 458


Accessing and Sharing Resources in Windows XP

(continued)


Accessing Shared Resources via UNIX/Linux and Specialized

Utilities• Network File System (NFS)

– provides file transfer capabilities

• NFS in Red Hat Enterprise Linux 3.0

– enable portmap

– enable rpc.mountd

– enable rpc.nfsd


Accessing Shared Resources via UNIX/Linux and Specialized

Utilities (continued)

• UNIX/Linux can access share Windows 2000/XP/Server 2003 with Samba


Accessing and Sharing Resources via Mac

OS X• In Mac OS X, you connect to another computer that is sharing a

disk or folder by using the Go menu

• To mount a shared drive

– open the Go menu

– select Connect To

Server

– enter address of

server


Accessing and Sharing Resources via Mac OS X

(continued)

• Establish the network identity and turn on file sharing through System Preferences

• Privileges are set in order to enable access


Sharing Printing Devices

• Operating systems discussed in this

book have the ability to share printers as

well as disks, directories, and files


Windows-based Systems

• Configure printing by using the Add Printer Wizard

• Once a printer is set up, it appears in the Printers folder

• In Windows XP and Windows Server 2003, click Start, and click Printers and Faxes

• Right-click the printer to access menu options


Windows-based Systems (continued)

• Windows 2000/XP/Server 2003 share permissions:– Print

– Manage Documents

– Manage Printers

– Special permissions


UNIX/Linux

• UNIX printing– log on to the UNIX server and printing to one of its

printers

– set up to use the BSD or the SVR4 spooling system as describe in Chapter 5

• Red Hat Enterprise Linux 3.0– GNOME Print Manager tool


NetWare

• Shared printing

– queue-based printing

– Novell Distributed Print Services (NDPS)


Mac OS X

• Methods of printer sharing

– can make a connected local printer available to other computers running the Mac OS on a network

– can attach to a shared printer offered by another workstation on the network


Network and Internet Resource Servers

• Resource Servers

– NetWare

– UNIX/Linux

– Windows 2000/Server 2003

– Mac OS X servers


Network and Internet Resource Servers

• Functions

– e-mail

– e-commerce

– video-conferencing

– multimedia

– client/server applications

– web servers


Summary

• Resource sharing is why networks exist and are thriving

• Security is important for network resources

• Groups, user accounts, and permissions permit or restrict access as determined by the administrator


Summary (continued)

• Client operating systems have utilities to

enable access or share resources over the

network

• Network server operating systems continue to

provide more and more ways to share

resources

Resource Sharing Over a Network Guide to Operating Systems Third Edition.

Documents

server windows server

client operating systems

file server

network guide

server netware slide

standalone server

server mapping

network windows