The Integrated File System (IFS)

A file system provides the support that allows applications to access specific segments of storage that are organized as logical units. These logical units are files, directories, libraries, and objects.

There are seven file systems in the integrated file system:
  • root (/)
  • Open Systems (QOpenSys)
  • Library (QSYS.LIB)
  • Document Library Services (QDLS)
  • LAN Server/400 (QLANSrv)
  • Optical Support (QOPT)
  • File Server (QFileSvr.400)
Figure 1 illustrates these file systems.

Users and application programs can interact with any of the file systems through a common integrated file system (IFS) interface. This interface is optimized for input/output of stream data, in contrast to the record input/output that is provided through the interfaces. The common integrated file system interface includes a set of user interfaces (commands, menus, and displays) and application program interfaces (APIs).

Figure 1. The Integrated File System Interface