13.05.2013 19:28, Lindsay Todd wrote: > Folks: On my cluster built on SL6.4, I need to deploy some VMs that > depend on other VMs: > > * db0 has no dependendencies > * ldap01,ldap02 require db0 to be running -- ordering constraint, but > no collocation (other than we'll use a collocation constraint to > recommend ldap01, ldap02 run on different physical hosts) > * bq01, bq02 depend on at least one of ldap01, ldap02 running > > At this point, I've got a test arrangement corresponding to only the > db01 and ldap01 resources being deployed, but it is enough to expose a > problem... > > The constraints themselves are quite simple. The trouble arises when we > try to migrate VMs. As the "Pacemaker Configuration Explained" manual > states: "The resource must not, directly or indirectly, depend on any > primitive or group resources." What is the reason for this restriction? > Sure enough, I can't migrate ldap01. I can migrate db01 successfully, > though it does force a stop/start on ldap01 (though that is really > unnecessary, since network connections would have been preserved). > > So is there a way to: > > * At least get the bq01, bq02 VMs able to migrate, though they depend > on other VMs? > * Be able to get the ldap01,ldap02 VMs to migrate, without forcing the > bq01,bq02 VMs to stop/start (unless both get stopped the restarted)? > * Be able to get the db01 resource to migrate, without forcing the > other dependents to stop/start, unless it is actually stop/started?
It seems to be exactly what was discussed a year ago here (http://www.mail-archive.com/pacemaker@oss.clusterlabs.org/msg12050.html) and then on bugtracker (http://bugs.clusterlabs.org/show_bug.cgi?id=5055). You may look at whitebox container implementation though, that may fit your needs. I didn't play with it yet, so that is just a guess. Alternative way would be to play with tickets as with cluster-wide attributes, but they are quite limited for that task I think. Vladislav _______________________________________________ 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