Backup made easy - How to protect your important data

With a backup, data can be saved on a suitable data carrier, such as an external hard drive. At the end of a backup, a backup copy is available that contains important data in so-called redundant form, i.e. as a duplicate. If old data is needed or if data is suddenly lost, all or part of the data can be restored with a backup. This can be done with manual methods (such as copying individual files) or with special backup software with restore functions.

In the private sphere, many users tend to see backups as optional. Yet each of us has important data on our hard drive or smartphone that we would not want to miss under any circumstances: Valuable souvenir photos that have accumulated over decades, a considerable music collection or digital financial documents.

Since even the backup itself is not immune to data loss - even the data backup can be damaged or destroyed - you should always keep more than one backup copy.

With regard to the data to be backed up, a basic distinction is made between two categories:

• Application data: When it comes to data backup in general, the so-called application data is usually the most relevant, as its loss would probably hit a company the worst. This is the information that was created by an employee or an application and saved on the computer or drive. Specifically, this can be, for example, text documents, photos, spreadsheets and related documents. Once this data is deleted, the process is usually irrevocable - unless you have taken precautions by regularly backing up your data.
• Operating systems and programmes: If certain files of the operating system or installed programmes are affected by malware, for example, this usually means that certain operations or programmes no longer function properly or, in the worst case, the entire operating system is paralysed. The user thus loses access to his or her data. Damage to the operating system is usually not too much of a problem, provided the necessary application data of the users or of a programme (e.g. databases) have been backed up by means of a data backup. The operating system of a server or computer can be reinstalled and the application data restored. It becomes more complicated if programmes have been modified to the user's own needs. Such configuration files should definitely be saved separately and be available in the data backup, otherwise all changes made will be lost in an emergency.

Backups can be made in different ways. Depending on the method chosen, a data backup requires more or less space. Since the different technical terms also occur within the data backup software, we have summarised the most important ones:

Full backup: A comlplete backup is not only the simplest type of data backup, but also probably the most effective backup method. With a full backup, all data on a computer or server is backed up - i.e. a 1:1 copy of the complete data stock. This method is very memory-intensive, as data is always backed up completely and thus several times if performed regularly. Of course, you can also simply overwrite an old complete backup - but this way you only have a backup of the last file status.

• Advantage: Simple backup and restore with only one backup file.
• Disadvantage: Time-consuming backup process with a very high memory requirement.

Incremental backup: The incremental backup is preferred by many backup programmes if several intermediate versions of the files are to be saved. First a full backup is made, then all files that have changed or been added since the last intermediate backup are regularly backed up.

• Advantage: Incremental backups require little memory and can be made quickly.
• Disadvantage: The full backup including all incremental backups is needed to restore data.

Differential backup: Differential backup works similarly to incremental backup: First, a full backup is created. Then, at regular intervals - for example once a day - all data that has been changed or added since the last full backup is backed up. The differential backups become larger and more extensive day by day, because with each differential backup the data already backed up in a previous differential backup is backed up again.

• Advantage: The differential backup requires more storage space, but can be performed much faster than a full backup.
• Disadvantage: Files that have only been changed once after the full backup are backed up again with each differential backup and require more storage space than incremental backups.

Choosing the right storage medium for data backup is essential. For private use, USB sticks, external hard drives or storage in a cloud are usually considered. Whether these media are also suitable as a storage location for data backups in the company should be carefully considered and depends on many factors. Common solutions for companies are e.g. NAS systems, RDX drives or magnetic tapes.