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<body class='hmmessage'><div dir='ltr'><br>Thank you for the prompt response!<br> <br>Anycase, due to luck of time we must start without a fencing device and only network. Is it possible with Pacemaker? <br>In the next release we will add fencing.<br>Can you send me link to doc?<br><br>BTW, may be you know if the first versions of Linux HA (before split of Pacemaker) also required a fence device?<br>Or was possible to use network only?<br><br>I appreciate your help!!! <br>Michael<br><br><div>> Date: Fri, 7 Jun 2013 11:04:36 -0400<br>> From: lists@alteeve.ca<br>> To: pacemaker@oss.clusterlabs.org<br>> CC: michael_furman@hotmail.com<br>> Subject: Re: [Pacemaker] Is possible to configure Pacemaker Active / Passive failover without hardware?<br>> <br>> It is possible in the same way that it is possible to drive on the <br>> highway without your seatbelt. First time something goes wrong though, <br>> you are in deep trouble. The biggest risk is a node that locks up but <br>> doesn't die. Any network based "detection" will not be able to tell the <br>> difference between a locked up node that may recover from a truly dead <br>> node. The only way to be sure is to fence it.<br>> <br>> So practically speaking, no, you must have fencing and the fence <br>> mechanism must be external to the node to be of use. The most common <br>> method is using a server's out of band management (IPMI, iLO, DRAC, <br>> etc). If you don't have this, then the APC brand AP7900 (or your <br>> country's version of) is an excellent switched PDU that works as a <br>> fantastic fence device. I frequently see these used for ~$200 (canadian).<br>> <br>> The 'fence_pcmk' is meant to hook cman's fencing into pacemaker's. It <br>> still requires a real fence device be setup in pacemaker.<br>> <br>> hth<br>> <br>> digimer<br>> <br>> On 06/07/2013 10:34 AM, Michael Furman wrote:<br>> > Dear Pacemaker community!<br>> > I want to install 2 Centos machines and to configure HA using one<br>> > virtual IP.<br>> > I do not want to use power card or something like this.<br>> > I want to use communication to determine the failing of nodes: broadcast<br>> > / mulicast UDP / TCP.<br>> ><br>> ><br>> > But I am confused if it possible. From one side I see here that the<br>> > failover is configured without any hardware:<br>> > http://clusterlabs.org/doc/en-US/Pacemaker/1.1-plugin/html-single/Clusters_from_Scratch/index.html#_perform_a_failover<br>> > On the second side I see that on quickstart and FAQ required a fencing<br>> > device (that is hardware):<br>> ><br>> > 1.On quickstart http://clusterlabs.org/quickstart-redhat.html you can<br>> > find the followowing commands: |ccs -f /etc/cluster/cluster.conf<br>> > --addfencedev pcmk agent=fence_pcmk|<br>> ><br>> > |2.|Similar here: http://clusterlabs.org/quickstart-ubuntu.html<br>> > |<fencedevice name="pcmk" agent="fence_pcmk"/>|||<br>> ><br>> > 3.http://clusterlabs.org/faq.html<br>> > Q: Do I need a fencing device?<br>> > A: Yes. Fencing is the only 100% reliable way to ensure the integrity of<br>> > your data and that applications are only active on one host. Although<br>> > Pacemaker is technically able to function without Fencing, there are a<br>> > good reasons SUSE and Red Hat will not support such a configuration.<br>> ><br>> > Please help!<br>> > Will be great if you provide the link to the appropriate documentation.<br>> ><br>> > Best regards,<br>> ><br>> > Michael<br>> ><br>> ><br>> ><br>> > _______________________________________________<br>> > Pacemaker mailing list: Pacemaker@oss.clusterlabs.org<br>> > http://oss.clusterlabs.org/mailman/listinfo/pacemaker<br>> ><br>> > Project Home: http://www.clusterlabs.org<br>> > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf<br>> > Bugs: http://bugs.clusterlabs.org<br>> ><br>> <br>> <br>> -- <br>> Digimer<br>> Papers and Projects: https://alteeve.ca/w/<br>> What if the cure for cancer is trapped in the mind of a person without <br>> access to education?<br></div> </div></body>
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