[vserver] vdir @ NFS? Permission errors.

Hi all,

first of all let me explain my current Linux-VServer setup:

* Raspberry Pi with Raspbian Wheezy.
* Custom 3.2.51 kernel with 2.3.2.16 VS patches.
* Everything stored on a single SDHC-card.

Maybe it's a little bit strange but it's running smoothly since 2012
:-)

Today I tried to move a VServer directory to a NFS share. The NFS
server is located on a Debian/armel machine with ext4 fs. I created
/vservers.nfs for this purpose and mounted the NFS share. I selected a
ClamAV/ClamSMTP guest for this test case.

> vserver example stop
> mv /vservers/example /vservers/example.bkp
> cp -av /vservers/example.bkp /vservers.nfs/example
> ln -s /vservers.nfs/example /vservers/example
> vserver example start

Nothing special here, everything is starting – looks fine! However:

> clamav error: /var/spool/clamsmtp/clamsmtpd.xxx: Access denied. ERROR
> clamav error: /var/spool/clamsmtp/clamsmtpd.xxx: lstat() failed:
> Permission denied. ERROR

The directory [/vservers.nfs/example]/var/spool/clamsmtp is owned by
clamsmtp:clamsmtp (102:104) on the guest and only readable by user/group
(0750). The user "clamav" is a member of the "clamsmtp" group. I've
double-checked the permissions but the user "clamav" can't access the
directory. The only solution is a chmod(755). Maybe I missed something
or misconfigured one part. When moving back to the local stored vdir
everything works as expected.

* Is it even possible to use a NFS share?
* Any ideas how I could fix it?

-- 
With kind regards,
Christian Schrötter