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<div class="moz-cite-prefix">On 07/24/2017 07:32 PM, Prasad,
Shashank wrote:<br>
</div>
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cite="mid:8A8F98BF0CDFD5438985D4397358E6C7ECC85E@idc.vanu.com">
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<div class="WordSection1">
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Sometimes
IPMI fence devices use shared power of the node, and it
cannot be avoided.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">In
such scenarios the HA cluster is NOT able to handle the
power failure of a node, since the power is shared with its
own fence device.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">The
failure of IPMI based fencing can also exist due to other
reasons also.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">A
failure to fence the failed node will cause cluster to be
marked UNCLEAN.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">To
get over it, the following command needs to be invoked on
the surviving node.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">pcs
stonith confirm <failed_node_name> --force<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">This
can be automated by hooking a recovery script, when the the
Stonith resource ‘Timed Out’ event.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">To
be more specific, the Pacemaker Alerts can be used for watch
for Stonith timeouts and failures.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">
<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">In
that script, all that’s essentially to be executed is the
aforementioned command.</span></p>
</div>
</blockquote>
<br>
If I get you right here you can disable fencing then in the first
place.<br>
Actually quorum-based-watchdog-fencing is the way to do this in a<br>
safe manner. This of course assumes you have a proper source for<br>
quorum in your 2-node-setup with e.g. qdevice or using a shared<br>
disk with sbd (not directly pacemaker quorum here but similar thing<br>
handled inside sbd).<br>
<br>
<blockquote type="cite"
cite="mid:8A8F98BF0CDFD5438985D4397358E6C7ECC85E@idc.vanu.com">
<div class="WordSection1">
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Since
the alerts are issued from ‘hacluster’ login, sudo
permissions for ‘hacluster’ needs to be configured.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Thanx.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<div style="border:none;border-left:solid blue 1.5pt;padding:0in
0in 0in 4.0pt">
<div>
<div style="border:none;border-top:solid #B5C4DF
1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal"><b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">From:</span></b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">
Klaus Wenninger [<a class="moz-txt-link-freetext" href="mailto:kwenning@redhat.com">mailto:kwenning@redhat.com</a>] <br>
<b>Sent:</b> Monday, July 24, 2017 9:24 PM<br>
<b>To:</b> Kristián Feldsam; Cluster Labs - All topics
related to open-source clustering welcomed<br>
<b>Subject:</b> Re: [ClusterLabs] Two nodes cluster
issue<o:p></o:p></span></p>
</div>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<p class="MsoNormal">On 07/24/2017 05:37 PM, Kristián
Feldsam wrote:<o:p></o:p></p>
</div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<p class="MsoNormal">I personally think that power off node
by switched pdu is more safe, or not?<o:p></o:p></p>
</blockquote>
<p class="MsoNormal"><br>
True if that is working in you environment. If you can't do
a physical setup<br>
where you aren't simultaneously loosing connection to both
your node and<br>
the switch-device (or you just want to cover cases where
that happens)<br>
you have to come up with something else.<br>
<br>
<br>
<o:p></o:p></p>
<div>
<p class="MsoNormal"><br>
<span
style="font-family:"Baskerville","serif"">S
pozdravem Kristián Feldsam<br>
Tel.: +420 773 303 353, +421 944 137 535<br>
E-mail.: <a href="mailto:support@feldhost.cz"
moz-do-not-send="true">support@feldhost.cz</a><br>
<br>
<a href="http://www.feldhost.cz" moz-do-not-send="true">www.feldhost.cz</a>
-<span class="apple-converted-space"> </span><b>Feld</b>Host</span>™<span
class="apple-converted-space"><span
style="font-family:"Baskerville","serif""> </span></span><span
style="font-family:"Baskerville","serif"">–
profesionální hostingové a serverové služby za adekvátní
ceny.<br>
<br>
FELDSAM s.r.o.<br>
V rohu 434/3<br>
Praha 4 – Libuš, PSČ 142 00<br>
IČ: 290 60 958, DIČ: CZ290 60 958<br>
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<br>
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Číslo účtu: 2400330446/2010<br>
BIC: FIOBCZPPXX<br>
IBAN: CZ82 2010 0000 0024 0033 0446</span> <o:p></o:p></p>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<blockquote style="margin-top:5.0pt;margin-bottom:5.0pt">
<div>
<p class="MsoNormal">On 24 Jul 2017, at 17:27, Klaus
Wenninger <<a href="mailto:kwenning@redhat.com"
moz-do-not-send="true">kwenning@redhat.com</a>>
wrote:<o:p></o:p></p>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<div>
<p class="MsoNormal" style="background:white"><span
style="font-family:"Baskerville","serif"">On
07/24/2017 05:15 PM, Tomer Azran wrote:<o:p></o:p></span></p>
</div>
<blockquote
style="margin-top:5.0pt;margin-bottom:5.0pt;font-variant-caps:
normal;orphans: auto;text-align:start;widows:
auto;-webkit-text-size-adjust:
auto;-webkit-text-stroke-width:
0px;background-color:rgb(255,
255,
255);word-spacing:0px">
<div>
<p class="MsoNormal" style="background:white"><span
style="font-size:11.0pt;font-family:"Arial","sans-serif"">I
still don't understand why the qdevice concept
doesn't help on this situation. Since the master
node is down, I would expect the quorum to
declare it as dead.<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal" style="background:white"><span
style="font-size:11.0pt;font-family:"Arial","sans-serif"">Why
doesn't it happens?<o:p></o:p></span></p>
</div>
</blockquote>
<p class="MsoNormal"><span
style="font-family:"Baskerville","serif""><br>
That is not how quorum works. It just limits the
decision-making to the quorate subset of the
cluster.<br>
Still the unknown nodes are not sure to be down.<br>
That is why I suggested to have quorum-based
watchdog-fencing with sbd.<br>
That would assure that within a certain time all
nodes of the non-quorate part<br>
of the cluster are down.<br>
<br style="font-variant-caps:
normal;text-align:start;-webkit-text-stroke-width:
0px;background-color:rgb(255,
255,
255);word-spacing:0px">
<br>
</span><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span
style="font-family:"Baskerville","serif""><br>
<br>
<o:p></o:p></span></p>
<div>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span
style="font-family:"Baskerville","serif"">On Mon,
Jul 24, 2017 at 4:15 PM +0300, "Dmitri Maziuk"<span
class="apple-converted-space"> </span><<a
href="mailto:dmitri.maziuk@gmail.com"
target="_blank" moz-do-not-send="true">dmitri.maziuk@gmail.com</a>><span
class="apple-converted-space"> </span>wrote:<o:p></o:p></span></p>
<div>
<pre>On 2017-07-24 07:51, Tomer Azran wrote:<o:p></o:p></pre>
<pre>> We don't have the ability to use it.<o:p></o:p></pre>
<pre>> Is that the only solution?<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>No, but I'd recommend thinking about it first. Are you sure you will <o:p></o:p></pre>
<pre>care about your cluster working when your server room is on fire? 'Cause <o:p></o:p></pre>
<pre>unless you have halon suppression, your server room is a complete <o:p></o:p></pre>
<pre>write-off anyway. (Think water from sprinklers hitting rich chunky volts <o:p></o:p></pre>
<pre>in the servers.)<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>Dima<o:p></o:p></pre>
<pre><o:p> </o:p></pre>
<pre>_______________________________________________<o:p></o:p></pre>
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<pre><o:p> </o:p></pre>
<pre>Project Home: <a href="http://www.clusterlabs.org/" moz-do-not-send="true">http://www.clusterlabs.org</a><o:p></o:p></pre>
<pre>Getting started: <a href="http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf" moz-do-not-send="true">http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf</a><o:p></o:p></pre>
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<p class="MsoNormal"><span
style="font-family:"Baskerville","serif""><br>
<br>
<br>
<o:p></o:p></span></p>
<pre>_______________________________________________<o:p></o:p></pre>
<pre>Users mailing list: <a href="mailto:Users@clusterlabs.org" moz-do-not-send="true">Users@clusterlabs.org</a><o:p></o:p></pre>
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<pre><o:p> </o:p></pre>
<pre>Project Home: <a href="http://www.clusterlabs.org/" moz-do-not-send="true">http://www.clusterlabs.org</a><o:p></o:p></pre>
<pre>Getting started: <a href="http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf" moz-do-not-send="true">http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf</a><o:p></o:p></pre>
<pre>Bugs: <a href="http://bugs.clusterlabs.org/" moz-do-not-send="true">http://bugs.clusterlabs.org</a><o:p></o:p></pre>
<p class="MsoNormal"
style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;font-variant-caps:
normal;text-align:start;-webkit-text-stroke-width:
0px;background-color:rgb(255,
255,
255);word-spacing:0px"><span
style="font-family:"Baskerville","serif""><o:p> </o:p></span></p>
<pre style="background:white;font-variant-caps: normal;text-align:start;-webkit-text-stroke-width: 0px;word-spacing:0px"><span style="font-size:12.0pt">-- <o:p></o:p></span></pre>
<pre style="background:white"><span style="font-size:12.0pt">Klaus Wenninger<o:p></o:p></span></pre>
<pre style="background:white"><span style="font-size:12.0pt"><o:p> </o:p></span></pre>
<pre style="background:white"><span style="font-size:12.0pt">Senior Software Engineer, EMEA ENG Openstack Infrastructure<o:p></o:p></span></pre>
<pre style="background:white"><span style="font-size:12.0pt"><o:p> </o:p></span></pre>
<pre style="background:white"><span style="font-size:12.0pt">Red Hat<o:p></o:p></span></pre>
<pre style="background:white"><span style="font-size:12.0pt"><o:p> </o:p></span></pre>
<pre style="background:white"><span style="font-size:12.0pt"><a href="mailto:kwenning@redhat.com" moz-do-not-send="true">kwenning@redhat.com</a> <o:p></o:p></span></pre>
<p class="MsoNormal"><span
style="font-family:"Baskerville","serif"">_______________________________________________<br>
Users mailing list:<span
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<br>
Project Home:<span class="apple-converted-space"> </span></span><a
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style="font-family:"Baskerville","serif""><br>
Getting started:<span class="apple-converted-space"> </span></span><a
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Bugs:<span class="apple-converted-space"> </span></span><a
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</div>
</blockquote>
</div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre class="moz-signature" cols="72">_______________________________________________
Users mailing list: <a class="moz-txt-link-abbreviated" href="mailto:Users@clusterlabs.org">Users@clusterlabs.org</a>
<a class="moz-txt-link-freetext" href="http://lists.clusterlabs.org/mailman/listinfo/users">http://lists.clusterlabs.org/mailman/listinfo/users</a>
Project Home: <a class="moz-txt-link-freetext" href="http://www.clusterlabs.org">http://www.clusterlabs.org</a>
Getting started: <a class="moz-txt-link-freetext" href="http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf">http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf</a>
Bugs: <a class="moz-txt-link-freetext" href="http://bugs.clusterlabs.org">http://bugs.clusterlabs.org</a>
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