<html><body><div style="color:#000; background-color:#fff; font-family:arial, helvetica, sans-serif;font-size:10pt"><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; "><span><br></span></div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; "><span>NFS is fine for read-only access to rrd data; in fact it's very fast.</span></div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; "><span><br></span></div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; "><span>NFS is not fine for mmap'ed writes to rrds from multiple sources (even from the same server.) Though building rrdtool with mmap disabled gets around that and with a proper flock'ing nfs client/server, it'll be fine ... with the inherent issue that write use of NFS like this on many files is likely going to be slow.</span></div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt;
"><br></div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; "><span style="font-size: 10pt; ">An architecture that works well is a rrd data node exports it's volume via NFS to a rrd ui server, so the data node only serves bytes out to the ui generator doing the computation/graph/exports/whatever.</span><br></div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; "><br></div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; ">Jo,</div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; "><br></div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; ">I'm curious, you say compiling your own resolved the issue, did you try compiling with mmap support? or only without?</div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; "><br></div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; ">I've never run
into this issue before (and store a <span style="font-weight: bold;">lot</span> of data) and on 64bit hosts, but:</div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; "><br></div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; "><span class="Apple-tab-span" style="white-space:pre"> </span>a) I always compile rrdtool not use stock OS rpm</div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; "><span class="Apple-tab-span" style="white-space:pre"> </span>b) It is compiled with mmap()</div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; "><span class="Apple-tab-span" style="white-space:pre"> </span>c) I only resize an rrdtool file when it's not being written to (my apps write daemon does the resize in place as a task.)</div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; "><br></div><div style="font-family: arial, helvetica, sans-serif;
font-size: 10pt; ">and it works for resizes just fine (just tested manually), I grew RRA 0 by 2x.</div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; "><br></div><div><div><span style="font-size: 13px;">[tmp]$ grep 1340865780 *xml</span></div><div><span style="font-size: 13px;">Epic_io_90.xml:<span class="Apple-tab-span" style="white-space:pre"> </span><!-- 2012-06-28 06:43:00 UTC / 1340865780 --> <row><v>9.7033939036e+04</v></row></span></div><div><span style="font-size: 13px;">resize.xml:<span class="Apple-tab-span" style="white-space:pre"> </span><!-- 2012-06-28 06:43:00 UTC / 1340865780 --> <row><v>9.7033939036e+04</v></row></span></div><div><span style="font-size: 13px;"><br></span></div><div><span style="font-size: 13px;">[tmp]$ grep 1340865840 *xml</span></div><div><span style="font-size: 13px;">Epic_io_90.xml:<span class="Apple-tab-span"
style="white-space:pre"> </span><!-- 2012-06-28 06:44:00 UTC / 1340865840 --> <row><v>9.7633476991e+04</v></row></span></div><div><span style="font-size: 13px;">resize.xml:<span class="Apple-tab-span" style="white-space:pre"> </span><!-- 2012-06-28 06:44:00 UTC / 1340865840 --> <row><v>9.7633476991e+04</v></row></span></div><div><br></div></div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; "><br></div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; ">-Ryan</div><div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; "><br></div> <div style="font-family: arial, helvetica, sans-serif; font-size: 10pt; "> <div style="font-family: 'times new roman', 'new york', times, serif; font-size: 12pt; "> <div dir="ltr"> <font size="2" face="Arial"> <hr size="1"> <b><span style="font-weight:bold;">From:</span></b> Steve Shipway
<s.shipway@auckland.ac.nz><br> <b><span style="font-weight: bold;">To:</span></b> Jo Rhett <jrhett@netconsonance.com> <br><b><span style="font-weight: bold;">Cc:</span></b> "rrd-users@lists.oetiker.ch" <rrd-users@lists.oetiker.ch> <br> <b><span style="font-weight: bold;">Sent:</span></b> Monday, July 16, 2012 7:28 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [rrd-users] rrdtool resize corrupts timestamps in both 1.3.9 and 1.4.7<br> </font> </div> <br>
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--></style><div><div class="yiv1618485047WordSection1"><div class="yiv1618485047MsoNormal">>Nope, they are on local storage. Anyway, what do you find "unlikely" ? </div><div class="yiv1618485047MsoNormal">>This is 100% reproducible across many machines, centos 5.4 all the way </div><div class="yiv1618485047MsoNormal">>through 5.8. Some with stock installed kernel, some with the very latest </div><div class="yiv1618485047MsoNormal">>from RedHat. I haven't tested yet on CentOS 6.x.</div><div class="yiv1618485047MsoNormal"><span style="font-size: 11pt; font-family: sans-serif; color: rgb(31, 73, 125); "> </span></div><div class="yiv1618485047MsoNormal"><span style="font-size: 11pt; font-family: sans-serif; color: rgb(31, 73, 125); ">It is the use of NFS to hold the RRD files that I find unlikely, not the existence of a bug in RRDTool. As we all know, bugs are always likely </span><span style="font-size: 11pt;
font-family: Wingdings; color: rgb(31, 73, 125); ">J</span><span style="font-size: 11pt; font-family: sans-serif; color: rgb(31, 73, 125); "></span></div><div class="yiv1618485047MsoNormal"><span style="font-size: 11pt; font-family: sans-serif; color: rgb(31, 73, 125); "> </span></div><div class="yiv1618485047MsoNormal"><span style="font-size: 11pt; font-family: sans-serif; color: rgb(31, 73, 125); ">My guess is that this is somehow connected to MMAP and 64bit kernels but I'm not familiar with that part of the RRDTool development. Best to see if Tobi can come up with anything – or anyone else on this list know?</span></div><div class="yiv1618485047MsoNormal"><span style="font-size: 11pt; font-family: sans-serif; color: rgb(31, 73, 125); "> </span></div><div class="yiv1618485047MsoNormal"><span style="font-size: 11pt; font-family: sans-serif; color: rgb(31, 73, 125); ">Steve</span></div><div class="yiv1618485047MsoNormal"><span
style="font-size: 11pt; font-family: sans-serif; color: rgb(31, 73, 125); "> </span></div><div><div class="yiv1618485047MsoNormal" align="center" style="text-align:center;"><span lang="EN-US" style="font-size: 11pt; font-family: sans-serif; color: rgb(31, 73, 125); "><hr size="2" width="100%" align="center"></span></div><div class="yiv1618485047MsoNormal"><b><span style="font-size: 11pt; font-family: sans-serif; color: rgb(31, 73, 125); ">Steve Shipway</span></b></div><div class="yiv1618485047MsoNormal"><span style="font-size: 10pt; font-family: sans-serif; color: rgb(31, 73, 125); ">ITS Unix Services Design Lead</span></div><div class="yiv1618485047MsoNormal"><span style="font-size: 10pt; font-family: sans-serif; color: rgb(31, 73, 125); ">University of Auckland, New Zealand</span></div><div class="yiv1618485047MsoNormal"><span style="font-size: 10pt; font-family: sans-serif; color: rgb(31, 73, 125); ">Floor 1, 58 Symonds Street,
Auckland</span></div><div class="yiv1618485047MsoNormal"><i><span style="font-size: 10pt; font-family: sans-serif; color: rgb(89, 89, 89); ">Phone: +64 (0)9 3737599 ext 86487</span></i></div><div class="yiv1618485047MsoNormal"><i><span style="font-size: 10pt; font-family: sans-serif; color: rgb(89, 89, 89); ">DDI: +64 (0)9 924 6487</span></i></div><div class="yiv1618485047MsoNormal"><i><span style="font-size: 10pt; font-family: sans-serif; color: rgb(89, 89, 89); ">Mobile: +64 (0)21 753 189</span></i></div><div class="yiv1618485047MsoNormal"><i><span style="font-size: 10pt; font-family: sans-serif; color: rgb(89, 89, 89); ">Email: <a rel="nofollow" ymailto="mailto:s.shipway@auckland.ac.nz" target="_blank" href="mailto:s.shipway@auckland.ac.nz"><span style="color:#595959;">s.shipway@auckland.ac.nz</span></a></span></i></div><div class="yiv1618485047MsoNormal"><span lang="EN-GB" style="font-size: 18pt; font-family: Webdings; color: green; ">P</span><span
lang="EN-GB" style="font-size: 11pt; font-family: sans-serif; color: blue; "> </span><span lang="EN-GB" style="font-size: 10pt; font-family: sans-serif; color: green; ">Please consider the environment before printing this e-mail</span><span lang="EN-GB" style="font-size: 11pt; font-family: sans-serif; color: blue; "> </span><span lang="EN-GB" style="font-size: 7.5pt; font-family: sans-serif; color: navy; "></span></div><div class="yiv1618485047MsoNormal"><i><span style="font-size: 10pt; font-family: sans-serif; color: rgb(31, 73, 125); "> </span></i></div></div><div style="border:none;border-left:solid blue 1.5pt;padding:0cm 0cm 0cm 4.0pt;"><div><div class="yiv1618485047MsoNormal"> </div></div></div></div></div></div><br>_______________________________________________<br>rrd-users mailing list<br><a ymailto="mailto:rrd-users@lists.oetiker.ch" href="mailto:rrd-users@lists.oetiker.ch">rrd-users@lists.oetiker.ch</a><br><a
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