Storage File virtualization:

File virtualization

The emergence of file virtualization products is the result of poor NAS management. NAS boxes lacked central management, and it was difficult to access files on all of the storage connected to NAS. File virtualization appliances create a layer between the file servers and the client boxes that access them. The layer manages files and file systems across servers, presenting client boxes with one logical file mount for every server, while the servers host the file data and metadata.