Hi, On Wed, Jun 17, 2009 at 12:55:41PM +0200, Ehlers, Kolja wrote: > Hello everybody, > > I am having problems understanding split brain situations. If I understand > correctly when a split brain situation happens the larger > cluster fragment have quorum and these cluster members can decide to fence > off resources or to stonith the cluster members which are > not seen. > > I have read that it is not sane to use a 2 node cluster, > because in split brain situations no one has quorum and the > no-quorum-policy decides how to deal with this.
There is no quorum in two-node clusters, so you set the policy to "ignore". You can use fencing to effectively replace it. > But what if I > have a 3 node cluster and the switch delivering the heartbeat > between those members dies. Then again I will have three > separate clusters each consisting of only 1 node and none > having quorum. Right. Make sure that your switch doesn't die. Or use more than one switch. > If I think of a split brain would it not be the best action to > merge all resources to the DC and the other node(s) will shut > down? Is this not possible to configure? No. Thanks, Dejan > Thanks for your help > > Kolja > > Gesch?ftsf?hrung: Dr. Michael Fischer, Reinhard Eisebitt > Amtsgericht K?ln HRB 32356 > Steuer-Nr.: 217/5717/0536 > Ust.Id.-Nr.: DE 204051920 > -- > This email transmission and any documents, files or previous email > messages attached to it may contain information that is confidential or > legally privileged. If you are not the intended recipient or a person > responsible for delivering this transmission to the intended recipient, > you are hereby notified that any disclosure, copying, printing, > distribution or use of this transmission is strictly prohibited. If you > have received this transmission in error, please immediately notify the > sender by telephone or return email and delete the original transmission > and its attachments without reading or saving in any manner. > > _______________________________________________ > Linux-HA mailing list > [email protected] > http://lists.linux-ha.org/mailman/listinfo/linux-ha > See also: http://linux-ha.org/ReportingProblems _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
