What is Virtual File System?
A virtual file system is a programming that creates an interface between an operating system’s kernal and a more concrete file system. In simple terms, it is an abstraction layer on top of a more concrete file system. The main purpose of a VFS is to permit client applications to access different types of concrete file systems in a consistent manner. A VFS, for example, can be used to access local and network storage devices transparently without the client application aware about the difference. It also manages the data storage and retrieval process amid the operating system and the storage sub-system. A VFS maintains a cache of directory lookups in order to enable easy location of frequently accessed directories or files. Some of the great examples of VFS are VMware Virtual Machine File System(VMFS), NTFS, Linux’s global file system (GFS), Oracle Clustered File System (OCFS).