System Administration Guide, Volume 1

Additional Virtual File Systems

These additional types of virtual file systems are listed for your information. They do not require administration.

Virtual File System 


FIFOFS (first-in first-out) 

Named pipe files that give processes common access to data

FDFS (file descriptors) 

Provides explicit names for opening files using file descriptors


Used mostly by STREAMS for dynamic mounts of file descriptors on top of files

SPECFS (special) 

Provides access to character special and block devices


File system used by the kernel for swapping