Digital data are important to every organization and obviously must not be lost. For that reason it should be backed up regularly. However, there are a number of disadvantages to a conventional backup on tape or external USB drive. For example you have to replace/attached the storage medium every day and save it outside your organization. Also the backup on USB or External sometimes fails or get corrupted. So stringent monitoring is necessary. Online backup with SAS has a number of major advantages compared to an ordinary backup. But the main advantage is that you no longer need to worry about it.