Debian kernel: "Server nfs-home reports our clientid is in use"

[Harald Dunkel <harald.dunkel@aixigo.de>]

Hi folks,

I have to admit I am running Wheezy and a Debian backport kernel
(3.16.7-ckt11-1~bpo70+1) on my NFServer and the clients, but maybe
somebody on this list can help.

Problem: Since the kernel upgrade it happens that a client looses
the NFS connection sometimes. The error message in kern.log on the
client says

Jul 30 15:53:57 dpcl082 kernel: [2880660.867248] NFS: Server nfs-home reports our clientid is in use
Jul 30 15:53:57 dpcl082 kernel: [2880660.867254] NFS: state manager: lease expired failed on NFSv4 server nfs-home with
Jul 30 15:54:54 dpcl082 kernel: [2880717.424872] NFS: Server nfs-home reports our clientid is in use
Jul 30 15:54:54 dpcl082 kernel: [2880717.424878] NFS: state manager: lease expired failed on NFSv4 server nfs-home with
Jul 30 15:55:01 dpcl082 kernel: [2880724.526741] NFS: Server nfs-home reports our clientid is in use
Jul 30 15:55:01 dpcl082 kernel: [2880724.526748] NFS: state manager: lease expired failed on NFSv4 server nfs-home with
:
:


The problem does not go away on its own. I have to umount and mount
/home on the client to get write access again. /var/log/kern.log on
the server doesn't mention this incident.

Since I saw "NFSv4.1: Fix client id trunking on Linux" introduced
early this year in the official kernel and included with 3.16.7-ckt7-1
into Debian's kernel I wonder if this rings a bell somewhere?

By now I saw this problem 4 times within the last week. I have more
than 100 NFS clients running 24/7, using a static NFS mount of /home
and /data. The problem appears to be hard to reproduce.


Every helpful comment is highly appreciated.

Regards
Harri