Considering the fact that antivirus software cannot catch up to the development of malware, the most rational choice is to build IT security around reserve copying systems. Instead of focusing solely on prevention, it is much easier and cheaper to recover your system from a backup. Moreover, reserve copying can mitigate the results of a force-majeure, human error or hardware failures. In this article, we will look into the advantages and disadvantages of the most common types of reserve copying.
A full backup creates a copy of the entire system every time, or copies of the files that you have chosen for reserve copying. The data is then archived to save space. This way, new archives appear in your storage periodically; most copies end up being redundant because the data remains unchanged since the last backup. This is a significant disadvantage because of ineffective resource usage: storage space, CPU time, the time it takes to create the copies, computing power and traffic resources used to transfer the archives. Full backups used to be common due to high reliability; nowadays, it is considered ineffective when used on its own. For example, full backups waste a lot of resources when the backup depth is low (less than two weeks) or if the frequency is high (once every 24 hours or once every couple of hours).
The dedupliction mechanism is often used to detect and delete copies of data in full backups. It is used both on the levels of the data storage or the server and the client itself. Deduplication can be quite effective: it can remove from 90% to 98% redundant copies. One of the few advantages of full backups is the recovery speed: when the data is recovered from a single archive, the process is faster than with incremental or differential backups. Nowadays, full reserve copying is most often used as the base, combined with other methods that use fewer resources. This data backup and recovery strategy is sometimes called a mixed or a synthetic backup.