Abstract: Cloud computing provides various kinds of services to its users. Storage-as-a-service is one of the services provided by cloud infrastructure in which large amount of electronic data is stored in cloud. As valuable and important data of enterprises are stored at a remote location on cloud we must be assured that our data is safe and be available at any time. In situations like Flood, Fire, Earthquakes or any hardware malfunction or any accidental deletion our data may no longer remain available. To maintain the data safety there must be some data backup techniques for cloud platform to recover valuable and important data efficiently in such situations mentioned above. This paper provides a review on various backup techniques used for cloud computing platform.

Keywords: Cloud computing, security issues, backup, threats, risks.