Hi, Andreas schrieb: > > On 03/22/2012 04:47 PM, Lentes, Bernd wrote: > > Hi, > > > > thanks for the quick response. So the data is not destroyed if two > > identicals VM's access the LV simultaneouslay ? I thought > > it would be. I > > will have stonith too. > > What is about live migration ? Is it possible with my setup ? > > Well, if you want live migration you must _not_ use an "exclusive" vg > but allow both nodes to access it simultaneously.
Ok. > > It is also possible to balance the VMs across the nodes. Running vm1 and vm2 on node1 and vm3 and vm4 on node2 ? > > The most important part in your setup regarding data protection is a > working STONITH setup ... and a correctly configured clvm > setup will not > allow a node to activate a vg and its lvs without consensus about the > cluster state and it coordinates changes to the metadata but > it does not > coordinate concurrent access to the data. > > That is within the responsibility of Pacemaker to start VMs > only on one > node ... and Pacemaker relies on STONITH to be certain about > node states. I thought that cLVM prevents data corruption, if two identical VM's access the corresponding lv simultaneously. Ok, it does not. I will have STONITH (HP ILO Network Adapter). Bernd Helmholtz Zentrum München Deutsches Forschungszentrum für Gesundheit und Umwelt (GmbH) Ingolstädter Landstr. 1 85764 Neuherberg www.helmholtz-muenchen.de Aufsichtsratsvorsitzende: MinDir´in Bärbel Brumme-Bothe Geschäftsführer: Prof. Dr. Günther Wess und Dr. Nikolaus Blum Registergericht: Amtsgericht München HRB 6466 USt-IdNr: DE 129521671 _______________________________________________ Pacemaker mailing list: Pacemaker@oss.clusterlabs.org http://oss.clusterlabs.org/mailman/listinfo/pacemaker Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org
