Laurent,<br><br> I never used DRDB (We have a SAN here...), or heartbeat either, but I suspect you will need to configure the OCFS2 timeouts to be larger than the heartbeat2 timeouts so that DRDB can resolve itself before the OCFS2 causes the machine to fence.<br><br> Also you probably will want to configure the heartbeat2 to use a third machine (try to ping a router for example) to decide which server to keep alive. When using Oracle the CRS stack uses the ethernet interface status to decide.<br><br>Regards,<br>Luis<br><br><b><i>Laurent Neiger <Laurent.Neiger@grenoble.cnrs.fr></i></b> wrote:<blockquote class="replbq" style="border-left: 2px solid rgb(16, 16, 255); margin-left: 5px; padding-left: 5px;"> Hi all,<br><br>We're building a 2-node cluster that we'd like to work in active/active <br>mode.<br>Since drbd 8.x this feature is possible so we hope to achieve a cluster <br>where<br>the 2 nodes would be able to share the load, not only one and the other
node<br>in stanby mode, waiting for the primary's failure...<br><br>In order to have a drbd active/active mode, we need to have a cluster <br>filesystem,<br>handling DLM. Our choice went to OCFS-2 for its numerous features.<br><br>But we encountered a problem : when we cut off the network link of, <br>let's say<br>node2, for simulating a crash, we managed to make node 1 fence node2 via <br>drbd<br>in order to avoid a split-brain configuration, but node1 then self-fence <br>itself<br>apparently due to ocfs2.<br><br>After some researches, we understood this seems to be a "normal" feature :<br>in a 2-node cluster, when communication (and so ocfs2 heartbeat) is lost,<br>the remaining node has no way to know if it's its peer which is down or<br>itself which is away from the cluster, so it self-fences.<br><br>Our first idea was so to add a third node, so that the 2 remainning nodes<br>still communicate and no ocfs2 self-fence is launched.<br><br>But ocfs2 heartbeat, as explained
in the FAQ, writes to the heartbeat <br>system file,<br>which has to be shared. If we set up a third node with a little ocfs2 <br>partition<br>and o2cb, it doesn't appear into the cluster, even when declared as <br>third node<br>in /etc/ocfs2/cluster.conf (of each node). Because the ocfs2 partition <br>on the<br>third node is not shared, so ocfs2 heartbeat is not shared.<br><br>If we run ocfs2_hb_ctl -I -d /dev/drbd0 on node0 and node1, we get back<br>the same reference for heartbeat, but a different one on node2 (third node).<br>And in /var/log/kern.log on node 0, we have<br>...<br>Feb 28 11:46:42 maq1 kernel: ocfs2_dlm: Node 1 joins domain <br>FB305B8298D94DCA9F9BF75D0AA09B8D<br>Feb 28 11:46:42 maq1 kernel: ocfs2_dlm: Nodes in domain <br>("FB305B8298D94DCA9F9BF75D0AA09B8D"): 0 1<br><br>But nothing about node2...<br><br>And we cannot share a common partition as drbd only works with 2 peers...<br><br>Would anyone have any hint about how we could solve this issue
?<br><br>Is there a way to make a 2-node ocfs2 cluster work<br>or must we have at least 3 nodes ?<br>But if 3 nodes are required, how to make it work with DRBD ?<br>Or in 2-node config., can we block self-fencing (but is it desirable) ?<br><br>Many thanks in advance for your help,<br><br>Best regards,<br><br>Laurent.<br><br>begin:vcard<br>fn:Laurent Neiger<br>n:Neiger;Laurent<br>org;quoted-printable:CNRS Grenoble;Centre R=C3=A9seau & Informatique Commun<br>adr:B.P. 166;;25, avenue des Martyrs;Grenoble;;38042;France<br>email;internet:Laurent.Neiger@grenoble.cnrs.fr<br>title;quoted-printable:Administrateur Syst=C3=A8mes & R=C3=A9seaux<br>tel;work:(0033) (0)4 76 88 79 91<br>tel;fax:(0033) (0)4 76 88 12 95<br>note:Certificats : http://igc.services.cnrs.fr/Doc/General/trust.html<br>x-mozilla-html:TRUE<br>url:http://cric.grenoble.cnrs.fr<br>version:2.1<br>end:vcard<br><br>_______________________________________________<br>Ocfs2-users mailing
list<br>Ocfs2-users@oss.oracle.com<br>http://oss.oracle.com/mailman/listinfo/ocfs2-users</blockquote><br><p> 
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