In a similar concept to cloud computing, cloud files is another service offered by various data center companies. Cloud computing gives you virtually unlimited processing power. Cloud files gives you virtually unlimited storage capacity.

Various companies purchase bulk storage capacities from data center providers and then offer unlimited storage for backup, photo albums or online disks on a pay per use basis to end users. These services are possible because storage systems have become very power efficient, cheap and most importantly, they are now available in very large capacities. By setting up a very large capacity storage system and allowing multiple users to access it, the economies of scale allow for low cost service while the service provider earns a profit.

Also, storage systems nowadays are scalable, with built-in redundancy and very fast. Multiple arrays of disks are used to create one large file system. The disks are usually setup in a RAID configuration that prevents data loss if a disk fails. The system administrator simply replaces that disk and the storage system automatically recovers the data.

This is possible because at list one disk in the RAID configuration is used as a parity disk which allows the storage system to calculate the missing data of a failed disk. When that failed disk is replaced, the missing data can be written on the replacement and the redundancy is restored. All this happens without the end user’s knowledge that a disk had failed.

Online disks are available from various providers starting from $0.15/GB/month.