It involves uniting multiple storage devices into a single logical pool of file.
Network file management (NFM) is a data storage management-related category.
The basic idea of NFM is that the rapid, ongoing growth of file data capacity on enterprise networks has led to massive management complexity and accelerating operating costs.
NFM is the concept of creating a virtualization layer between the clients and the file servers (or NAS devices).
By creating this abstraction layer, System Administrators may simplify the management of multiple storage devices, including non-disruptive movement of data between servers, preserving the client access path (pathname), policies for automating the placement of data according to its changing needs, and the ability to discover, analyze and report on server and file usage.