The virtual file system (VFS) interface, also known as the v-node interface, provides a bridge between the physical and logical file systems. The information that follows discusses the virtual file system interface, its data structures, and its header files, and explains how to configure a virtual file system.
There are two essential components in the file system:
| Logical file system | Provides support for the system call interface. |
| Physical file system | Manages permanent storage of data. |
The interface between the physical and logical file systems is the virtual file system interface. This interface allows support for multiple concurrent instances of physical file systems, each of which is called a file system implementation. The file system implementation can support storing the file data in the local node or at a remote node. For more information on the virtual filesystem interface, see Understanding the Virtual File System Interface.
The virtual file system interface is usually referred to as the v-node interface. The v-node structure is the key element in communication between the virtual file system and the layers that call it. For more information on v-nodes, see Understanding Virtual Nodes (V-nodes).
Both the virtual and logical file systems exist across all of this operating system family's platforms.