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In The Name Of Allah Whose Blessings Are Uncountable. Introduction to Operating System Abdul Hameed Assistant Professor http://informationtechnology.pk www.facebook.com/it4all.pk 3 Lecture Overview • Operating System Concepts • Disk Partitioning • Primary/ Extended /Logical Partition • Formatting • FAT / NTFS • NTFS Securities Abdul Hameed 4 System Software • What is system software? Programs that control operation of computer Two types are operating systems and utility programs Operating system (OS) (sometimes called the platform) coordinates all activities among computer hardware resources Abdul Hameed Operating Systems • Functions of an operating system? 5 start the computer provide a user interface manage programs administer security manage memory control a network provide file management and other utilities monitor performance establish an Internet connection schedule jobs and configure devices Abdul Hameed 6 Operating System Software that controls a computer and acts as a layer between the hardware and the applications and users. (eg. Linux, Windows, Mac OS X, Unix); Software that provides a simple environment / Interface for programmers and end users to work more efficiently (shell, command interpreter) Abdul Hameed 7 Operating System: User interface Controls how you enter data and instructions and how information displays on screen command-line interface menu-driven interface Difficult to remember and use Give more control Abdul Hameed 8 Operating System: Graphical user interface (GUI) User interacts with menus and visual images such as icons and buttons Abdul Hameed 9 Operating System: Single user/ Single tasking Working on one programs by one user Like DOS OS Single user/ multitasking Working on two or more programs that reside in memory at same time Like Windows XP Abdul Hameed 10 Operating System: Network operating system Allows users to share printer, Internet access, files, and programs on a network Administers security by establishing user name and password for each user Abdul Hameed 11 Operating System: Types Some characteristics of operating systems Proprietary software Devicedependent Runs only on specific type of computer Privately owned and limited to specific vendor or computer model Downward compatible Works with application software written for earlier version of operating system Deviceindependent Runs on many manufacturers’ computers Upward compatible Runs on new versions of operating system Abdul Hameed 12 Operating System: Categories Windows CE.net Pocket PC 2002 Palm OS Symbian OS DOS Win 3.x,95, 98,2000 professional, Me, NT workstation, Windows XP Mac OS X OS/2 UNIX Linux Embedded Netware Windows NT Server, 2000 Server, 2003 OS/2 Warp Server UNIX Linux Solaris Network Stand-alone Abdul Hameed 13 Network Operating System •Examples of NetWare network operating systems Designed for client/server networks Linux Windows Server 2003 Multi-purpose operating system Upgrade to Windows 2000 Server Solaris Version of UNIX developed by Sun Microsystems Specifically for e-commerce applications Abdul Hameed Introduction to Disk Partitions Abdul Hameed Assistant Professor http://informationtechnology.pk www.facebook.com/it4all.pk 15 Disk Management: Primary Partition • A volume you create using unallocated space on a basic disk. Windows 2000 and other operating systems can start from a primary partition. • You can create up to four primary partitions on a basic disk, or three primary partitions and an extended partition. • Primary partitions can be created only on basic disks and cannot be sub partitioned. Abdul Hameed 16 Disk Management: Extended Partition A portion of a basic disk that can contain logical drives. One can extended partition if one want to have more than four volumes on your basic disk. Only one of the four partitions allowed per physical disk can be an extended partition. Extended partitions can be created only on basic disks. Abdul Hameed 17 Disk Management: Logical Partition • A volume you create within an extended partition on a basic disk. • A logical drive can be formatted and assigned a drive letter. • Only basic disks can contain logical drives, and a logical drive cannot span multiple disks. Abdul Hameed 18 Disk Management: Partition Table On master boot record (MBR) disks, you can create up to four primary partitions, or you can create up to three primary partitions and one extended partition. Within the extended partition, you can create unlimited logical drives. On GUID partition table (GPT) disks, you can create up to 128 primary partitions. Because GPT disks do not limit you to four partitions, you do not need to create extended partitions or logical drives. Abdul Hameed Introduction to File System Abdul Hameed Assistant Professor http://informationtechnology.pk www.facebook.com/it4all.pk 20 File Systems File systems are a data structure or a collection of files used by the operating system (i.e Windows, Mac OS) to organize data and programs. FAT 16 FAT 32 NTFS EXT2 Abdul Hameed 21 File Systems: FAT 16 Used for DOS, Windows 3.1x Maximum partition size is 4GB Maximum File size is 2GB OS like Unix, Linux, OS/2, Windows also read FAT16 That is why suitable in case of Multi boot option. Abdul Hameed File Systems: FAT 32 22 ◦ Introduced in 1996 with windows 95 ◦ Maximum partition size is 2TB ◦ Maximum File size is 4GB ◦ Improving the disk space usage by reducing the size of cluster ◦ Do not provide Security Encryption Disk Quota Compression Abdul Hameed 23 File Systems: NTFS Provide local security of files and folders Compression to save the disk space Disk quota management to manage the storage Encryption for additional security Abdul Hameed 24 File Systems: NTFS: Advantages With NTFS, individual files and folders can have assigned Access Rights, enabling the user to have greater control over the security in the system. NTFS supports data compression and encryption for files and folders, allowing the user to save space on his hard drive and keep his files more secure. The largest file that can be saved using FAT32 is 4 Gigabytes. With NTFS there is no such limit. On large drives with many files, the performance of a FAT32 drive suffers. NTFS drives do not have a problem handling many files. Abdul Hameed 25 File Systems: NTFS: Advantages This new file system also facilitates indexing of file contents, which makes it far faster to do things such as use the Windows Find/search function to seek a word processing document by looking for a word buried deep in its text. Abdul Hameed 26 File Systems: NTFS: Advantages Microsoft has tested NTFS with a single partition of up to 19 Terabytes (TB), but the theoretical maximum is at least 8 Petabytes (PB). By contrast, FAT32 is effectively limited to volume sizes of 2TB (although this point is debatable, and this is a theoretical maximum). One of the big differences is that FAT32 doesn't scale as well as NTFS. The larger the volume size in FAT32, the larger the cluster size. At 64GB, FAT32 moves up to 16K clusters. Even a 512byte file uses 16K of space just to exist under FAT32 on a 64GB volume. That means FAT32 does not store data efficiently on larger volumes. Abdul Hameed 27 File Systems: NTFS: Advantages NTFS is able to keep to its 4K cluster size default even on huge disk volumes. Link tracking. You know how under Win98 if you create a desktop shortcut for something, if you move that target file, the shortcut is broken? Not so under XP with NTFS, which can dynamically update file shortcuts by automatically searching for the new location of the target file. Abdul Hameed Introduction to Profiles Abdul Hameed Assistant Professor http://informationtechnology.pk www.facebook.com/it4all.pk 29 Profiles Contains the configuration information related to the user and it contains User’s Desktop arrangement Program Items Personal Program Groups Network and printer connections Screen colors Mouse settings Abdul Hameed 30 Profiles Windows Explorer View of windows Explorer Mapped network drives etc. Control Panels Accessibility options Keyboards and mouse preferences Taskbar All settings including program items and their properties Accessories Preference settings for Calculator, Command Prompt, notepad etc. Abdul Hameed Online Help bookmarks 31 Profiles Users Profiles are useful when multiple users share the same computer. User Profiles can be used by a single user or by group of users Three types of users profiles Local User Profiles Roaming User Profiles Mandatory user Profiles Abdul Hameed 32 Profiles: Local User Profile First time the user logon the user receive the default user profile. Created on the local computer under the folder ‘Document and Setting’ and match with the user name Contains the files NTUSER.DAT file and some subfolders contain the link to user’s Desktop items. Abdul Hameed 33 Profiles: Drawbacks of Local User Profile Available only on the computers where they were created. How to overcome the drawback? By using Roaming User Profiles Abdul Hameed 34 Profiles: Roaming User Profile Stored on the Server and accessible from any client When a user logon to client, a roaming profiles from server downloaded to local computer When logoff or shutdown the client, roaming profile uploaded/saved on the server If the roaming profile inaccessible from the server then local user profile is used. In this way the roaming profile moves as the user moves in the network. Abdul Hameed 35 Profiles: Roaming User Profile: How to? Create the local user profile that will be used as roaming user profile Create user, login as new user, customize it. Create a folder on the server and share the newly created folder Copy the profile to the server shared folder (under the User Profile tab of System Properties choose the Copy To option) E.g. \\server1\profiles\abc (where server1 is name of server, profiles is the shared folder and abc is name of user. Abdul Hameed 36 Profiles: Roaming User Profile: How to? Select user under the local user and groups utility-right click – properties – profile tab and enter the path of the profile. i.e. \\server1\profiles\abc Abdul Hameed 37 Profiles: Mandatory User Profile A roaming profile that cannot be modified by the user is called Mandatory user profile. Mandatory profiles are stored in the file named as NTUSER.MAN as compare to NTUSER.DAT of Roaming profile A user can change the profile but it cannot be saved on the server when he logoff. Abdul Hameed 38 Profiles: Mandatory User Profile: How to? Create the local user profile that will be used as mandatory user profile Create user, login as new user, customize it. Create a folder on the server and share the newly created folder Rename the file NTUSER.DAT to NTUSER.MAN Copy the profile to the server shared folder (under the User Profile tab of System Properties choose the Copy To option) E.g. \\server1\profiles\abc (where server1 is name of server, profiles is the shared folder and abc is name of user. Abdul Hameed 39 Profiles: Mandatory User Profile: How to? Select user under the local user and groups utility-right click – properties – profile tab and enter the path of the profile. i.e. \\server1\profiles\abc Abdul Hameed Introduction to Groups Abdul Hameed Assistant Professor http://informationtechnology.pk www.facebook.com/it4all.pk 41 Groups: Importance Groups are used to logically organize the users with similar rights. Assign the permission to groups instead of many users By adding users to groups, the users will get all the permissions of the Groups Similarly by removing the permission from the group will revoke the relevant permissions from all the users of the groups. Groups simplify troubleshooting Abdul Hameed 42 Groups: Default Groups Administrators Group Has full permissions Can grant themselves the required permissions Backup Operators Has permission to backup and restore the file system even if they don’t have NTFS permission Does not have direct access to all the file system – Only through backup utility Abdul Hameed 43 Groups: Default Groups Guests Has limited access to the computer Used for the users who are not regular Most administrator don’t allow guest access. Power Users Has fewer access than Administrators e.g. Create local user and groups Create and delete network shares Create manage local printers Stop/start services etc. Abdul Hameed 44 Groups: Default Groups Replicator Support directory replication Only domain users can be a member of Replicator Group Users Have very limited system access. Abdul Hameed Introduction to NTFS Permission Abdul Hameed Assistant Professor http://informationtechnology.pk www.facebook.com/it4all.pk 46 NTFS Permissions Control access the permission to NTFS folders and files Allow and Deny permissions Deny overrides allow Permission are Cumulative Abdul Hameed 47 NTFS Permissions: Full Control Traverse folder and execute file List folder’s content and read the files in it. See the folder’s or file’s attributes Change the folder’s or file’s attributes Create new files and overwrite data to the files. Create new folder and append data to file Delete subfolders and files Delete files Change permission for files and folder Take ownership Abdul Hameed 48 NTFS Permissions: Read, Execute Traverse folder and execute files List the contents of folder and read data in files See the folder’s or file’s attribute Abdul Hameed 49 NTFS Permissions: Read List the contents of folder and read the data in the folder’s files See the folder’s or file’s attributes Write Change the file’s or folder’s attribute Create new files and write data to files Create new folders and append data to files Abdul Hameed 50 NTFS Permissions: Inherited By default parent folder permission are also applied to the subfolders or files in that folder These are called the inherited Permission Inherited Permission are displayed in grayed check mark. One can override the permission inheritance (Stop inheritance) for the folder by un-checking the allow inheritable permission from parent to propagate to this object. You will then be given the choice of either to copy or remove the permission previously inherited by the object. Abdul Hameed 51 NTFS Permissions: Files are Copied or Moved Move files If moved within the same NTFS volume the NTFS permission retained as original. If move file or folder to another folder of different volume the file is treated as copy and will have the same permission as the destination folder Abdul Hameed 52 NTFS Permissions: Files are Copied or Moved Copy files If the file or folder copied on another folder (either on the same volume or different volume) the file will have the same permission as of destination folder. If copied or moved file to FAT volume, it will not retain any NTFS permission Abdul Hameed
