from
The Free On-line Dictionary of Computing (8 July 2008)
installable file system
<operating system> (IFS or "File System Driver", "FSD") An
{API} that allows you to extend {OS/2} to access files stored
on disk in formats other than {FAT} and {HPFS}, and access
files that are stored on a {network file server}.
For example an IFS could provide programs running under OS/2
(including DOS and Windows programs) with access to files
stored under {Unix} using the {Berkeley fast file system}.
The other variety of IFS (a "remote file system" or
"redirector") allows file sharing over a {LAN}, e.g. using
Unix's {Network File System} {protocol}. In this case, the
IFS passes a program's file access requests to a remote file
server, possibly also translating between different file
attributes used by OS/2 and the remote system.
Documentation on the IFS API has been available only by
special request from IBM.
An IFS is structured as an ordinary 16-bit {DLL} with entry
points for opening, closing, reading, and writing files, the
swapper, file locking, and {Universal Naming Convention}. The
main part of an IFS that runs in {ring} 0 is called by the
OS/2 {kernel} in the context of the caller's process and
{thread}. The other part that runs in ring 3 is a utility
library with entry points for FORMAT, RECOVER, SYS, and
CHKDSK.
EDM/2 article (http://edm2.com/0103/).
(1999-04-07)