Fault tolerance

Is the manner in which a system responds to hardware or software failure. It is the system’s ability to allow for failures or malfunctions, and this ability may be provided by software, hardware, or both. To handle faults gracefully, some computer systems have two or more duplicate systems.

File system virtualization

Is the process of integrating multiple file systems into one large virtual file system, so that users can access data objects through the virtual file system without being aware of underlying partitions.

File virtualization

Refers to the creation of an abstract layer between file servers and clients that access those file servers.

Filer

Is an intelligent network node whose hardware and software is designed to provide file services to client computers.