Samba and NFS server on same system using same filesystems

[Nico Kadel-Garcia]

On Thu, Dec 8, 2016 at 11:11 AM, Volker Lendecke <vl at samba.org> wrote:
> On Thu, Dec 08, 2016 at 09:39:48AM -0600, Ron Short wrote:
>> What issues might one run into having both a NFS server and a Samba
>> configuration running on the same system serving out the same filesystem(s)?
>
> It should work fine as long as you don't actually have interoperating
> applications that require any form of interoperable locking.

I've done it. I've also done it transitively, with a NetApp publishing
NFSv4 shares to a Samba server for general NFS performance, and Samba
publishing CIFS shares on top of the NFSv4. That got.... well, NFSv4
support and integration with Samba is *possible*, but they don't
exactly match. It was much more stable, but not accepted by my
employer, to use NFSv3 for *everything* to simplify privileges and
gain performance, and activate NFS support on the Windows boxes.

I realize that's not what Samba was written for, but it was more
stable at the time (roughly 6 years ago) to rely on NFS and simple
POSIX credentials rather than support the complexities. NFSv4 support
may have improved since then.

> For example samba hands out oplocks, nfsv4 I believe calls them
> delegations. When a SMB client has an oplock, and an NFS client wants
> that file, the NFS server must somehow trigger samba to release the
> oplock. This is done on Linux with kernel oplocks. Similar issues
> arise with share modes vs share reservations.
>
> In general, if you don't have applications that actually compete on
> the same file space, you should be fine. But if you do, we need to
> talk :-)
>
> Your mail address is sgi.com. Is this IRIX, or Linux, or something
> else? Just curious...
>
> Volker