Re: BHYVE on NFSv4.2 filesystem?

On Mon, May 18, 2026 at 3:01 PM Dan Shelton <[email protected]> wrote:
>
> On Mon, 18 May 2026 at 23:49, Rick Macklem <[email protected]> wrote:
> >
> > On Mon, May 18, 2026 at 2:27 PM Dan Shelton <[email protected]> wrote:
> > >
> > > On Fri, 20 Feb 2026 at 01:21, Bakul Shah <[email protected]> wrote:
> > > >
> > > > On Feb 19, 2026, at 11:45 AM, Dan Shelton <[email protected]> wrote:
> > > > >
> > > > > On Wed, 18 Feb 2026 at 22:45, Dan Shelton <[email protected]> wrote:
> > > > >>
> > > > >> Hello,
> > > > >>
> > > > >> Has anyone tried a BHYVE with a disk as file on a NFSv4.2 mount?
> > > >
> > > > Yes. [I tried this on a 15.0-RELEASE-p3 host, nfsv4.2 mounting
> > > > a filesystem from a 15.0-STABLE machine]
> > >
> > > How about the performance? Is it better than iSCSI?
> > >
> > > >
> > > > >
> > > > > And does BHYVE disk emulation send a NFSv4.2 DEALLOCATE if the disk
> > > > > gets a TRIM cmd?
> > > >
> > > > No idea.
> > >
> > > Which tool can be used to figure that out? dtrace on the FreeBSD
> > > NFSv4.2 client? Rick?
> > Ask google's ai.
> >
> > I just typed "does zfs use trim" and it gave me an answer
> > that looks legit. Is it correct? I don't know, but if you don't
> > think so, find a ZFS wizzard.
> >
> > ZFS is the only local fs that supports DEALLOCATE at this
> > time, so it is up to ZFS.
>
> No, the question is whether the BHYVE disk emulation uses deallocate()
> to free blocks, and the FreeBSD NFSv4.2 client translates deallocate()
> to NFSv4.2 DEALLOCATE
Look for fspacectl() in the bhyve sources with find/grep.
(fspacectl() is the FreeBSD syscall that does VOP_DEALLOCATE()/
DEALLOCATE.

rick

>
> Dan
> --
> Dan Shelton - Cluster Specialist Win/Lin/Bsd
>