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<p class="MsoNormal"><span style="font-size:11.0pt">Hi,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">I have a setup where I have multiple docker instances on a base linux (Node1).<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">I have a cluster inside each docker instances which pair with a similar setup on another node (node2) and form 2 node clusters.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">See pic1 below.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">In this setup, the cluster status etc resides in the docker overlay file system I presume.<o:p></o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt"><Query1></span></b><span style="font-size:11.0pt"> Is there a clear list of files which have the cluster status (Basically data of corosync, pacemaker, sbd, crmsh processes I think)?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt"><Query2></span></b><span style="font-size:11.0pt"> In this setup if I wanted the cluster data to be persistent across “remove and re-run of the docker instance”, what can I do?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Presuming cluster data will be in /var, /etc, /usr folders, I tried the following solution.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Created volumes for var, etc and usr and then during docker run used the options like “-v var_vol:/var -v etc_vol:/etc -v usr_vol”<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">With this some portion worked and saw some weird behaviour as well.<o:p></o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:11.0pt"><Query3></span></b><span style="font-size:11.0pt"> Is this a correct way of solving the problem to have a persistent cluster data? Have I missed mapping any folder?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">FYI, I have given the details about the experiment I tried to verify if the cluster data is consistent below (Experiment).
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Let me know if this makes sense.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><u><span style="font-size:11.0pt">Pic1<o:p></o:p></span></u></b></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><img width="947" height="532" style="width:9.8645in;height:5.5416in" id="Picture_x0020_3" src="cid:image002.png@01DB9DC0.635B6FA0"></span><span style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><u><span style="font-size:11.0pt">Experiment<o:p></o:p></span></u></b></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Tried the following experiment. Please let me know if this makes sense<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">1) In a proper working cluster, stopped app-1-on-node-2 container on node2 to get the following crm status in app-1-on-node-1<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><i><span style="font-size:11.0pt">Node List:<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:11.0pt"> * Online: [ app-1-on-node-1 ]<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:11.0pt"> * OFFLINE: [ app-1-on-node-2 ]<o:p></o:p></span></i></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">2) Stopped and started the app-1-on-node-1 and checked the crm status. Remained the same as before<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><i><span style="font-size:11.0pt">Node List:<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:11.0pt"> * Online: [ app-1-on-node-1 ]<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:11.0pt"> * OFFLINE: [ app-1-on-node-2 ]<o:p></o:p></span></i></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">3) Remove the container app-1-on-node-1 and run it newly and then checked the crm status.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> Now the status was changed by not showing the app-1-on-node-2 (Presume the reason for this is old cluster data is not available)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><i><span style="font-size:11.0pt;background:yellow;mso-highlight:yellow">Node List:<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:11.0pt;background:yellow;mso-highlight:yellow"> * Online: [ app-1-on-node-1 ]</span></i><i><span style="font-size:11.0pt"><o:p></o:p></span></i></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">4) Repeated the step 1 and observed the crm status (This time I used “-v var_vol:/var -v etc_vol:/etc -v usr_vol" during docker run)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><i><span style="font-size:11.0pt">Node List:<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:11.0pt"> * Online: [ app-1-on-node-1 ]<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:11.0pt"> * OFFLINE: [ app-1-on-node-2 ]<o:p></o:p></span></i></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">5) Remove the container app-1-on-node-1 and run it newly (with “-v var_vol:/var -v etc_vol:/etc -v usr_vol" during docker run) and then checked the crm status.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"> <o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">6) Now checked the crm status<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p></o:p></span></p>
<p class="MsoNormal"><i><span style="font-size:11.0pt;background:lime;mso-highlight:lime">Node List:<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:11.0pt;background:lime;mso-highlight:lime"> * Online: [ app-1-on-node-1 ]<o:p></o:p></span></i></p>
<p class="MsoNormal"><i><span style="font-size:11.0pt;background:lime;mso-highlight:lime"> * OFFLINE: [ app-1-on-node-2 ]</span></i><i><span style="font-size:11.0pt"><o:p></o:p></span></i></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Deva.<o:p></o:p></span></p>
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