Just for the history/other users the resolution of the problem Steve had:

OpenVZ was installed on XFS, while Xen used ext3 file system.
XFS doesn't support filetype feature (d_type field returned by readdir()/getdents64()),
so d_type is always reported as DT_UNKNOWN.

nrpe application from Debian Sarge repository has a bug
(fixed in Etch?), so it didn't handle files with unknown types and thus
didn't saw config files.

Steve switched to ext3 file system and the problem has gone.

Thanks,
Kirill



Steve Wray wrote:
> Hi there,
> I just took some filesystems from servers which have been running under 
> Xen for some time and converted them to openvz.
> 
> I've found a very strange issue.
> 
> We monitor our servers with Nagios and each server runs the Nagios nrpe 
> server.
> 
> Our config system for Nagios involves several Nrpe config files in 
> /etc/nagios/nrpd.d/ and a config directive in nrpe.cfg pointing to this 
> directory with:
> 
> include_dir=/etc/nagios/nrpe.d
> 
> I have found that while this directive works under Xen this does not 
> work under openvz.
> 
> I've tested this by taking the filesystem back and forth between Xen and 
> Openvz and it is definitely only a problem in Openvz.
> 
> Also, our VMs are running Debian.
> 
> Debian Etch does not exhibit this problem; only Debian Sarge.
> 
> I'm at a loss to explain this... it seems really wierd.
> 
> /proc/user_beancounters shows no failcnt for anything.
> 
> Surely I am missing something here? Any advice on debugging this would 
> be appreciated.
> 
> 
> 
> Thanks