Types of backup

There are a number if different types of backup that can be useful for minimising the amount of time it takes for the backup to complete.

1) Full system backup

A full system backup is where the entire system, all of the files including documents, videos, pictures, system files are backed up. If the file is on the disk it will be backed up. These backups are very useful when your system hardware fails and they contain all the information needed to restore the system back to what it was when the backup was taken.

Pros:

• All files are backed up
• The system can be completed recovered from a full backup

Cons:

• Since all files are being backed up the time to complete can be long

2) Factory image

This is a special type of backup as it does not contain any user data. It is a backup that can be used to restore a system to the state it was in when it was first purchased.

Pros:

• Easy to reset the system to factor settings
• Only needs to be created once

Con:

• Does not contain any user data

3) Incremental

An incremental backup only backs up files that have been changed since the last backup (either full or incremental). Files that have not been changed are not backed up. This makes the backup smaller and faster. However, to completely restore a system requires the full backup to be restored first and then all subsequent incremental backups. Also, the incremental backup that contains a specific file is not always known.

A typical way incremental backups are used is to take a fully backup on the weekend and incremental backups each weekday.

Pros:

• Faster than a full backup
• Take up less space than a full backup

Cons:

• Take longer to recover a compete system
• Can be difficult to find a specific file to restore

4) Continuous backups

These are backups that run continuously. These types of backups are sometime called synchronisation.  When change is made to a file, that file is automatically backed up straight away. This has the advantage of always having a backup copy of the latest version of a file. However, it does add additional load to a system as all changes need to be monitored so they can be backed up immediately.

Often cloud storage such as OneDrive and iCloud have this functionality turned on so files are always backed up and previous versions can be restored.

Pros:

• No loss of data
• Can restore multiple versions of a file

Cons:

• Extra load on a system, especially when lots of large files are being updated regularly
• Space required to store multiple versions of files