OPERATING SYSTEM - UTILITIES SOFTWARE, DOS OS AND VIRTUALIZATION

UTILITIES SOFTWARE:

Utility program: Type of software that performs a specific task, usually related to managing or maintaining the computer system. Many utilities are built into operating systems (for finding files, viewing images, backing up files, etc.) Utilities are also available as stand-alone products and as security.

Examples of Utilities Software:

1- Search tools: Designed to search for files on the user’s hard drive. Windows Vista includes new search tools

2- Diagnostic programs: Evaluate your system and make recommendations for fixing any errors found

3- Disk management programs: Diagnose and repair problems related to your hard drive

4- File compression programs: Reduce the size of files so they take up less storage space on a storage medium or can be transmitted faster over the Internet.

Example is

– Both zip and unzip files

– WinZip (Windows users) and Stuffit (Mac users)

5- Uninstall utilities: Remove programs from your hard drive without leaving bits and pieces behind. Uninstall capabilities are built into most operating systems. Uninstall utility programs are also available as stand-alone programs. Sometimes an uninstall option is included in a program’s folder when that program is originally installed. Important to properly uninstall programs, not just delete them

6- Cleanup utilities: Designed to delete temporary files.

7- Backup and recovery utilities: Make the backup and restoration process easier.

Backup: Duplicate copy of data or other computer content. Good backup procedures are critical for businesses and individuals. Individuals should back up important documents, e-mail, photos, home video, etc. Store backup data on a CD or DVD, second hard drive, flash memory drive, or upload to the Internet. Back up your entire PC once all programs have been installed, so your system can be restored to that configuration.

8- Security programs: Protect computers and users.

The examples are as follows:

– Antivirus programs

– Antispyware programs

– Firewalls

– Many are included in Windows and other operating systems.

DISK OPERATING SYSTEM (DOS)

HISTORY

MS-DOS 1.0 was released in August 1981, and was updated until April 1994 when it was replaced by Windows 95. All versions of windows still contain some type of DOS, in windows 95 and 98 you can go to run and type command to get to DOS prompt, in NT, 2000, and XP you can type CMD and get DOS.

MS-DOS Prompt

The prompt in MS-DOS displays your current directory.

C:\dos\commands> means you are in that directory, and any command you use will apply to the current directory unless you specify a different one.

Basic Commands CD

1- CD- Change directory

You use this command when you want to change the directory.

Example: CD C:\DOS will bring you to the dos folder

2- CD.. - brings you to the previous directory.

Example: if you are in C:\DOS\FOLDER

3- CD.. Will bring you to C:\DOS

4- COPY will copy the file from one location to another

Example COPY A:\file.txt c:\ will copy the file from a:\ to c:\

5- XCOPY can move files, directories, and whole drives from one location to another, It is more powerful than the copy command, and has a lot of switches.

6- DIR will display the contents of the folder

7- DEL will delete a file or an empty directory from the drive

8- EDIT will open a text file

9- MOVE will move the file or directory from one location to another

Example: MOVE a:\file.txt c:\file.txt will move the file to the c:\ drive

10- REN will rename the file

Example: REN file.txt myfile.txt will rename the file.txt to myfile.txt

11- MD is used to make a directory (folder) in MS-DOS.

Example: MD myfolder will make a folder called myfolder in current directory

12- DELTREE command will delete the folder and all of its contents, including other folders.

Example: DELTREE C:\myfolder will delete the folder and all the contents.

13- TREE shows you all of the folders and files in current directory like explorer in windows.

14- CLS Will clear the contents of the screen

Attributes

Attributes are the properties of a file such as hidden, read-only, archive or system file.

In MS-DOS you can view/change attributes with the attrib command.

Example: attrib +r file.txt will make the file read-only.

The Help Switch /?

You can use the help switch with any command. It will give you the command structure, and the available switches.

Virtualization of Operating System

Virtualization is the creation of a virtual rather than actual version of something, such as an operating system, a server, a storage device or network resources.

You probably know a little about virtualization if you have ever divided your hard drive into different partitions. A partition is the logical division of a hard disk drive to create, in effect, two separate hard drives.

The evolution of virtualization

Operating system virtualization is the use of software to allow a piece of hardware to run multiple operating system images at the same time. The technology got its start on mainframes decades ago, allowing administrators to avoid wasting expensive processing power.

How virtualization works

Virtualization describes a technology in which an application, guest operating system or data storage is abstracted away from the true underlying hardware or software. A key use of virtualization technology is server virtualization, which uses a software layer called a hypervisor to emulate the underlying hardware. This often includes the CPU's memory, I/O and network traffic. The guest operating system, normally interacting with true hardware, is now doing so with a software emulation of that hardware, and often the guest operating system has no idea it's on virtualized hardware. While the performance of this virtual system is not equal to the performance of the operating system running on true hardware, the concept of virtualization works because most guest operating systems and applications don't need the full use of the underlying hardware. This allows for greater flexibility, control and isolation by removing the dependency on a given hardware platform. While initially meant for server virtualization, the concept of virtualization has spread to applications, networks, data and desktops.