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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 defragmentation

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.

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

Data 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.

Backups

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.

Virus scanning

Antivirus software scans a computer system, either when activated or automatically at a specified date and time, and identifies potential viruses. Many antivirus software programs can also delete or fix potential threats once they have been identified.

Firewall

A firewall is a network security system that monitors incoming and outgoing network traffic and blocks content based on predetermined rules. It works as a barrier to protect the users on the network from untrusted or undesirable content, typically from the internet.

System monitoring

System monitoring is used to monitor the resources and performance of a computer system, such as central processing unit (CPU) usage or the amount of free RAM (random-access memory).

Task management

Task management software provides information about the processes and applications currently running on a computer. This can be used to identify why a computer may be running slowly. It highlights all tasks that the CPU is currently performing, including those that are hidden from the user.

Disk scanning and repair

This allows a system to detect and, if possible, recover from physical errors on the disk. It scans disk surfaces for defects and marks those sections as unavailable to prevent the rewriting of data and data loss.