Practical Experience with OS/2 Installable File Systems

The installable file system (IFS) facility on OS/2 offers an efficient mechanism for expanding the abilities of the OS/2 kernel. Two prototypes illustrate the usefulness of the IFS facility. An OS/2 port of the Andrew File System (AFS) allows users to access global community files while retaining the private local tile system on the OS/2 machine. An IFS implementation of a network protocol mapper, which maps TCP/IP socket calls to SNA Advanced program-to-program Communication (APPC) calls, provides the ability to run any socket program on an APPC network after simply re-linking with the mapping library. The only impediment to the development of these prototypes is the lack of kernel-level interfaces to operating system devices, resulting in time-consuming data movement back up to the user level to access the network and the local disks. This impediment will disappear as OS/2 and its associated support software matures.