When googling for File System Switch or Virtual File System most sources mention Sun NFS
and SysVr3 as the earliest implementations. Some sources mention 8th Edition.
I did a (short) search on FSS/VFS in earlier, non-Unix OS’s (Tenex, Multics, CTSS, etc.),
but none of those seem to have had a comparable concept.
Does anybody recall prior art (prior to 1984) in this area?
Paul