Have you considered using AoE (Coraid)? It would require dedicated fossil, NFS CIFS servers, but they'd all be sharing the storage -- Coraid supports ext4 and NTFS. Most servers have multiple NICs, which makes a dedicated LAN for AoE traffic easy.

Regarding authentication and access control, I think the only *standard* option for a mixed OS environment (Plan 9, Linux/*BSD, Windows) is Kerberos.

It would be great if factotum could handle Kerberos 5. There is a pure Go package (https://github.com/jcmturner/gokrb5) that could help. Of course, this would take some work.

This setup would require 4 (or potentially only 3) machines:

* AoE block storage

* the KDC (MIT, Heimdal, or MS Active Directory)

* Plan 9 file server (fossil, but also CIFS and NFS servers)

* Linux or NetBSD file server for CIFS and NFS

-Skip

On Fri, Aug 31, 2018 at 10:22 PM Lucio De Re <lucio.dere@gmail.com> wrote:

My hope is to provide a central file server that fulfills reliable
file services to both Plan 9 and Linux as seamlessly as possible. I am
willing to sacrifice a few Unix features, such as file links, in that
file server, if I can dedicate it to a narrower role than to support
the full Linux environment. In Plan 9 parlance, I only need file
services, not computing capabilities and the file server is allowed to
limit some of the computing needs involved (like, say, graphics, any
multimedia stuff, even mouse use).

The question, then, is what file service will satisfy these needs,
including access control, automatic backup as provided by default
under Plan 9, etc. I am not very fond of Linux's propensity to need
daily upgrades, but Plan 9 has quirks of its own, which I would be
hard pressed to enumerate here, but we are all aware of.

Lucio.