Major issues with nfsv4

Alan Somers asomers at
Fri Dec 11 23:44:55 UTC 2020

On Fri, Dec 11, 2020 at 4:39 PM Rick Macklem <rmacklem at> wrote:

> Alan Somers wrote:
> [stuff snipped]
> >That's some good information.  However, it must not be the whole story.
> I've >been nullfs mounting my NFS mounts for years.  For example, right now
> on a >FreeBSD 12.2-RC2 machine:
> If I recall, you were one of the two people that needed to switch to
> "minorversion=1" to get rid of NFSERR_BADSEQID (10026) errors.
> Is that correct?

In fact, yes.  Though that case had nothing to do with nullfs or jails.

> >> sudo nfsstat -m
> >Password:
> > on /usr/home
> >nfsv4,minorversion=1,tcp,resvport,soft,cto,sec=sys,acdirmin=3,acdirmax=60,acreg>min=5,acregmax=60,nametimeo=60,negnametimeo=60,rsize=65536,wsize=6553>6,readdirsize=65536,readahead=1,wcommitsize=16777216,timeout=120,retrans=>2147483647
> Btw, using "soft" with NFSv4 mounts is a bad idea. (See the BUGS section of
> "man mount_nfs".)

Grahh.  I forgot that was in there.  I can't remember why I put that
there.  These days I agree with you, and advise other people to use hard
mounts, too.  Thanks for point it out.

> If you have a hung NFSv4 mount, you can use
> # umount -N /usr/home
> to dismount it. (It may take a couple of minutes.)
> rick
> > mount | grep home
> on /usr/home (nfs, nfsv4acls)
> /usr/home on /iocage/jails/rustup2/root/usr/home (nullfs)
> Are you using any mount options with nullfs?  It might be worth trying to
> make the read-only mount into read-write, to see if that helps.  And what
> does "jls -n" show?
> -Alan

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