The correct backup strategy for a business depends on a number of factors. The size of the business and its budget, dependence on IT, resources, restoration time and other business-specific requirements have to be taken into consideration. Many experts recommend the 3-2-1 rule. It sets out the minimum requirements for a responsible backup strategy and can be applied to companies of almost any size and IT budget. This rule ensures that data are protected at three levels, eliminating most data loss risks.
3-2-1 backup rule
Keep three copies of your digital data. The first one is the version that you work with productively. The other two copies are backups.
Store your digital data on at least two different types of storage media (e.g. NAS and cloud).
Keep at least one copy of your digital data off-site. Nowadays, hacker attacks are increasingly aimed directly at the back-ups of companies or private customers. In order to increase the probability of a successful ransomware attack, they encrypt or delete backups. To prevent such attacks, it is strongly recommended to use methods such as offline backups or unalterable backups (using WORM technology - Write Once Read Many). Important: it is imperative that it is impossible to manipulate, damage, destroy or steal the created data copies.