Operating systems - EduqasUtility software - including disk compression

Purpose and functionality

Utility software helps maintain the system. Utility software is used for:

• defragmentation
• data compression
• backups
• virus scanning
• firewalls
• system monitoring
• task management
• disk scanning and repair

Disk defragmenters

When a file is stored on a hard disk it is not stored as a whole file, but as a series of segments. Sometimes the segments run together in sequence (see File 1) and sometimes the segments are split up over a disk (see File 3). This is known as fragmentation.

Over time, more and more files become fragmented. A fragmented disk takes longer to read from and write to, making a computer run slower.

Disk defragmenter utility takes the fragmented files and rearranges the segments so that they run contiguously. This decreases read/write time, thereby speeding up computer performance.

Disk compression

Compression software reduces the size of a file stored on secondary storage.

Smaller files are easier to transmit across a network as they require fewer packets to be sent. Their reduced size also means more files can be stored in any given area of storage.

Clipboard manager

The clipboard manager is a program that keeps track of the most recently copied or cut data. It allows the user to “go back” and use that data, such as copied text or an image.

System profiles

These are used when more than one person uses the same computer or computer system. System profiles are used to personalise the environment for the user, for example features such as desktop wallpaper, personal preferences and network settings.

Backups and backup software

Data can be lost accidentally or deliberately. A user may accidentally delete or overwrite a file or a hard disk may fail, preventing access to any files stored on it. A hacker or malicious user may deliberately delete or overwrite data.

To prevent data loss, regular copies of the data should be made. A copy of data is known as a backup. Backups can contain a copy of all files on a computer, or just those specified by a user.

Network managers - also known as network administrators - make regular backups of all files on a network using backup software. The software automatically makes a backup at a scheduled time of day, usually during the evening when the network is quiet. Backups are usually made to a high capacity secondary storage device or to the cloud.

If data loss occurs, data can be retrieved from the backup. The software allows all backed-up files to be retrieved, or just specified files. This can be done with a system restore.

Two types of backup are possible:

• full backup
• incremental backup

A full backup involves making a copy of every file on the computer or network. They can require a lot of storage space and can be time consuming to make.

Incremental backups take a copy of any new files created since the last backup or of any files that have been edited, such as user documents.

Most network managers make an initial full backup and then switch to daily incremental backups. This way all data is backed up and daily backups are small and less time consuming.

Disk checkers

Disk checkers are a type of utility software that is used to scan a hard drive to identify any errors such as corrupted files on the disk.

Disk formatters

Disk formatters are used to prepare a device like a hard drive for first use or to be used again. Disk formatters erase everything on a storage device when they are run.