Virtual File Systems

What is the purpose of the Virtual File System (VFS) in UNIX?

To transparently support multiple file systems on the same system simultaneously.

Where is the VFS layer positioned in the UNIX system architecture?

It was added as a separate layer on top of the file system module, working with multiple file system modules.

How did VFS maintain compatibility with existing applications?

It supported the same API as the existing file systems so applications wouldn't need to change.

How does VFS handle file system requests?

It examines requests by looking at file system tree nodes to determine the correct file system module, then passes the request to that module.

What happens after a file system module completes a request?

It returns control to the VFS module, which then returns control to the calling application.

What was the architectural change when VFS was introduced?

A new abstraction layer was added between applications and multiple file system modules.