[TUHS] Re: NFS 40th anniversary event

On Wed, Aug 13, 2025 at 10:00 AM Douglas McIlroy <douglas.mcilroy(a)dartmouth.edu> wrote: I believe it did? If I recall correctly, it was available with System V, though perhaps I am misremembering. I have no doubt that RFS was technically superior to NFS, but Sun had non-technical market advantages. Assuming that I am remembering correctly, I suspect it was unsuccessful commercially for two reasons: 1. Sun gave NFS (and the associated RPC layer) away for free, under a particularly liberal license, which lead to lots of interoperability (Larry's and Dave's comments notwithstanding). I suspect by the time RFS was available, it was much more expensive and less interoperable across heterogeneous systems. 2. Sun was quite adamant that NFS be stateless, and also not tied to Unix filesystem semantics, whereas (as I understood it) RFS was both stateful and deeply imbued with Unix semantics. Related to (2), while the File System Switch that was developed to support RFS was very elegant, I think that Sun's "vnode" architecture was seen as more flexible, permitting Unix to incorporate support for all sorts of foreign filesystem types (useful when CD-ROMs and things like floppy disks using the MS-DOS FAT format started becoming common). I suppose RFS could have been adapted to use vnodes, but by then it probably wasn't considered worth the effort due to lack of adoption. It may be worth mentioning that some NFS implementations are configurable for UID remapping in the server. I recall Sun environments with NFS and NIS (the mechanism for distributing /etc/passwd, groups, and other administrative data around a network). It was a really pleasant environment, and extremely productive. Properly configured, you could log into essentially any machine on the network and have access to your home directory, common data, locally installed programs (that of course lived on NFS), and so on. It was quite common to tell a colleague to just have a look in your home directory for something you were working on, facilitating collaboration, and so on. Diskless and "dataless" machines were common; the latter being machines that mounted _most_ things from a central NFS server, but had the operating system itself (really, /, /usr and /tmp) locally installed on a disk. It required a lot of effort to maintain, since Unix machines were still fundamentally meant to be standalone, and it wasn't as elegant as Plan 9 ultimately was, but it was very nice for the time. - Dan C.