Thanks for the responses! In fact, the issue was resolved already on Friday (response was posted in the Zenoss community thread <a href="http://community.zenoss.org/thread/18663">http://community.zenoss.org/thread/18663</a>, but could not update this thread until now):<div>
The problem was indeed with the permissions: server had connections limited by hosts file and following change was required in <span style="color:rgb(43,43,43);font-family:Arial;font-size:12px;line-height:20px">/etc/hosts.allow</span>: </div>
<div><span style="color:rgb(43,43,43);font-family:Arial;font-size:12px;line-height:20px"><br></span></div><div><span style="color:rgb(43,43,43);font-family:Arial;font-size:12px;line-height:20px">rrdcached: localhost</span><br>
</div><div><p style="border:0px;border-collapse:collapse;border-spacing:0px;font-size:12px;list-style:none;margin:0px;outline:0px;padding:0px;color:rgb(43,43,43);font-family:Arial;line-height:20px"><br></p><p style="border:0px;border-collapse:collapse;border-spacing:0px;font-size:12px;list-style:none;margin:0px;outline:0px;padding:0px;color:rgb(43,43,43);font-family:Arial;line-height:20px">
Now the data is collected correctly. Of course, one could try improving rrdcache's error message in the future, albeit it seems all logical now.</p><p style="border:0px;border-collapse:collapse;border-spacing:0px;font-size:12px;list-style:none;margin:0px;outline:0px;padding:0px;color:rgb(43,43,43);font-family:Arial;line-height:20px">
<br></p><p style="border:0px;border-collapse:collapse;border-spacing:0px;font-size:12px;list-style:none;margin:0px;outline:0px;padding:0px;color:rgb(43,43,43);font-family:Arial;line-height:20px">Br,</p><p style="border:0px;border-collapse:collapse;border-spacing:0px;font-size:12px;list-style:none;margin:0px;outline:0px;padding:0px;color:rgb(43,43,43);font-family:Arial;line-height:20px">
Juha</p></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Mon, Nov 5, 2012 at 6:45 AM, Steve Shipway <span dir="ltr"><<a href="mailto:s.shipway@auckland.ac.nz" target="_blank">s.shipway@auckland.ac.nz</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div lang="EN-NZ" link="blue" vlink="purple"><div><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Rrdcached is one of the parts of rrdtool that is rapidly developing. It may be that the Zenoss application requires a more recent version in order to get additional options.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">However the error seems to indicate that your problem lies more at the filesystem end; possibly the rrdcached cannt read the required file due to ownerships, permissions, or simply process limits such as the max open file descriptors (to fix this latter, update the limits.conf and restart the rrdcached process). My tentative guess at this point would be the ‘nofile’ setting in limits.conf preventing the file from being opened.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Steve<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><div class="MsoNormal" align="center" style="text-align:center"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><hr size="2" width="100%" align="center">
</span></div><p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Steve Shipway</span></b><b><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u><u></u></span></b></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#1f497d">ITS Unix Services Design Lead<u></u><u></u></span></p><p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#1f497d">University of Auckland, New Zealand<u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#1f497d">Floor 1, 58 Symonds Street, Auckland<u></u><u></u></span></p><p class="MsoNormal"><i><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#595959">Phone: <a href="tel:%2B64%20%280%299%203737599%20ext%2086487" value="+6493737599" target="_blank">+64 (0)9 3737599 ext 86487</a><u></u><u></u></span></i></p>
<p class="MsoNormal"><i><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#595959">DDI: <a href="tel:%2B64%20%280%299%20924%206487" value="+6499246487" target="_blank">+64 (0)9 924 6487</a><u></u><u></u></span></i></p>
<p class="MsoNormal"><i><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#595959">Mobile: <a href="tel:%2B64%20%280%2921%20753%20189" value="+6421753189" target="_blank">+64 (0)21 753 189</a><u></u><u></u></span></i></p>
<p class="MsoNormal"><i><span style="font-size:10.0pt;font-family:"Calibri","sans-serif";color:#595959">Email: <a href="mailto:s.shipway@auckland.ac.nz" target="_blank"><span style="color:#595959">s.shipway@auckland.ac.nz</span></a><u></u><u></u></span></i></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:18.0pt;font-family:Webdings;color:green">P</span><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:blue"> </span><span lang="EN-GB" style="font-size:10.0pt;font-family:"Arial Narrow","sans-serif";color:green">Please consider the environment before printing this e-mail</span><span lang="EN-GB" style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:blue"> </span><span lang="EN-GB" style="font-size:7.5pt;font-family:"Verdana","sans-serif";color:navy"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1f497d"><u></u> <u></u></span></p><div style="border:none;border-left:solid blue 1.5pt;padding:0cm 0cm 0cm 4.0pt">
<div><div style="border:none;border-top:solid #b5c4df 1.0pt;padding:3.0pt 0cm 0cm 0cm"><p class="MsoNormal"><b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span lang="EN-US" style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> rrd-developers-bounces+steve=<a href="mailto:steveshipway.org@lists.oetiker.ch" target="_blank">steveshipway.org@lists.oetiker.ch</a> [mailto:<a href="mailto:rrd-developers-bounces%2Bsteve" target="_blank">rrd-developers-bounces+steve</a>=<a href="mailto:steveshipway.org@lists.oetiker.ch" target="_blank">steveshipway.org@lists.oetiker.ch</a>] <b>On Behalf Of </b>Juha Mustonen<br>
<b>Sent:</b> Friday, 2 November 2012 9:23 p.m.<br><b>To:</b> <a href="mailto:rrd-developers@lists.oetiker.ch" target="_blank">rrd-developers@lists.oetiker.ch</a><br><b>Subject:</b> [rrd-developers] Internal error while talking to rrdcached<u></u><u></u></span></p>
</div></div><div><div class="h5"><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">Hi,<u></u><u></u></p><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">I'm getting following error from Zenoss monitoring setup, but the root cause is unclear. <u></u><u></u></p>
</div><div><p class="MsoNormal">Possibly you could give some insight or tips where to look at? Already tried via Zenoss community forum (<a href="http://community.zenoss.org/thread/18663" target="_blank">http://community.zenoss.org/thread/18663</a>) but no luck there so far.<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">[Error]<u></u><u></u></p></div><div><div><p class="MsoNormal">2012-11-02 10:20:32,411 ERROR zen.ThresholdInstance: Unable to read RRD file for usedBlocks_usedBlocks<u></u><u></u></p>
</div><div><p class="MsoNormal">Traceback (most recent call last):<u></u><u></u></p></div><div><p class="MsoNormal"> File "/opt/zenoss/Products/ZenModel/ThresholdInstance.py", line 150, in checkRaw<u></u><u></u></p>
</div><div><p class="MsoNormal"> cycleTime, rrdType = self._getRRDType(dataPoint)<u></u><u></u></p></div><div><p class="MsoNormal"> File "/opt/zenoss/Products/ZenModel/ThresholdInstance.py", line 173, in _getRRDType<u></u><u></u></p>
</div><div><p class="MsoNormal"> data = rrdtool_fn()<u></u><u></u></p></div><div><p class="MsoNormal"> File "/opt/zenoss/Products/ZenUtils/Utils.py", line 1739, in _inner<u></u><u></u></p></div><div><p class="MsoNormal">
return fn(*args,**kwargs)<u></u><u></u></p></div><div><p class="MsoNormal"> File "/opt/zenoss/Products/ZenModel/ThresholdInstance.py", line 172, in rrdtool_fn<u></u><u></u></p></div><div><p class="MsoNormal">
return <a href="http://rrdtool.info" target="_blank">rrdtool.info</a>(self.context().path(dp), *rrd_daemon_args())<u></u><u></u></p></div><div><p class="MsoNormal">error: request: internal error while talking to rrdcached<u></u><u></u></p>
</div></div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">[Process] <u></u><u></u></p></div><div><p class="MsoNormal">zenoss 12303 0.0 0.0 114288 1156 ? Ssl 10:06 0:00 /usr/bin/rrdcached -b /opt/zenoss/perf -p /opt/zenoss/var/rrdcached.pid -l /opt/zenoss/var/rrdcached.sock -j /opt/zenoss/var/rrd_journals<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">Is there any (rrdcached?) command that I could run/tryout test whether the problem really is in rrdtool/rrdcached ?<u></u><u></u></p>
</div><div><p class="MsoNormal"><u></u> <u></u></p></div><div><p class="MsoNormal">Br,<br>Juha<u></u><u></u></p></div></div></div></div></div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br>Juha<br>
</div>