A comprehensive survey on data storage and retrieval

Sensitive data of the user present in the storage server has to be highly available, secured and also accessible from anywhere as per the user requirements. This paper provides a preventive maintenance approach, so that even if the main storage server containing the sensitive data of the user fails, that data can be retrieved by the user. This is achieved by copying the data blocks to both main storage server and backup server simultaneously during the upload process. So that even if main storage server fails, the data needs of the user can be served by the backup server. Since the sensitive data as to be securely stored, instead of directly uploading the sensitive data file, the data file will be broken into data blocks and these blocks are encrypted and stored in the storage server. So that even if a intruder gains access to the storage server and tries to access the data, he will not be able to retrieve the data file as he cant determine which block belongs to which file and also the blocks are encrypted. By this we are securely storing the personal data and also providing the preventive maintenance for this data so as to be highly available.