SVR4 vs BSD (was AIX (is it unix)?)

[Mike Eisler]

In article <chris at mimsy.UUCP> writes:
>Oh.  This I do not really understand, since the RFS mechanisms are pretty
>much equivalent to the VFS mechanisms, except that instead of
>
>	vnode->vn_op(vnode, arg1, arg2)
>
>one writes
>
>	(*fsswitch[inode.fstype])(inode, arg1, arg2)

	RFS - remote file sharing. A distributed network file system from
		AT&T
	FSS - File System Switch. In SVR3 an inode based file system switching
		mechanism. In SVR4, a vnode based file system switching
		mechanism.
	VFS - Virtual File System. In SunOS 2.0 to 4.x, as well as NFSSRC 2.0 to
		4.0, a vnode based file system switching mechanism.  As
		Sun as gone on record as saying they will support SVR4,
		one can expect the VFS to be superceded in future
		versions of SunOS by SVR4's FSS.

The fsswitch[] directives Chris is describing represent SVR3's FSS. RFS is
(nominally) an entry in SVR3's FSS, just at the System V file system (from
AT&T), and NFS (from Lachman and others) are entries (not nominally) of the FSS.
To understand why RFS is nominally an entry of the FSS, see Chartock's
paper in Summer USENIX (Phoenix) '87.

	-Mike Eisler	mre at pyramid.com