Thanks for the answer, I suspected that failover domains could do the trick, I will try this solution. Anyway, shutdown is for me still unclear. starting up a cluster involves starting the cman daemon, clvmd, gfs, mounting the gfs filesystems and starting rgmanager. Stopping cman does not work on a cluster, because the other nodes still think that the shutting down node is up, and they end fencing it if it is no more responding. In fact, the shutdown procedures of a single node involves the removeal of the node from both the fencing and cman agents (fence_tool remove and cman_tool leave remove commands). So stopping the daemons is not enough. Beside this, the ordered shutdown of a physical/virtual cluster requires the shutdown of the virtual first then of the physical cluster. Paolo > Hi Paolo, > > >> When the physical cluster starts up, and the nodes are operational, the >> virtual nodes are started in an unordered mode, e.g. the allocation to >> the >> physical nodes is not predetermined. If the physical cluster nodes come >> up >> at different times, the first operational node of the physical cluster >> tries to bring up all the virtual guests, even if the available memory >> is >> not sufficient. This causes some instabilities at system startup, and >> requires some manual intervention in order to distribute the xen guests >> among the physical cluster nodes. >> >> Is there some way to prevent this kind of behaviour ? >> > > yes there is. Basically what you want to do is the same thing that is > done with nfs services in the nfs cookbook. > you basically create three failoverdomains, one for each node, with > ordered=1, then put your nodes in with a priority of 2 except one node > which gets priority of 1. every domain then has to have a different node > with the priority of 1. > then all you have to do is put the vms in the failoverdomain with the > node you want it to be started on automagically, so in case you have > failoverdomain1 with node2 having priority 1, you put > domain="failoverdomain1" in your <vm> definition. > this will also do some migration magic if your cluster is up. so if a > node has to take over a vm that's in a failoverdomain with a failed node > having the highest priority, it will automatically migrate the vm back, > once the higher priority node has become available again. > > >> Another aspect is related to system shutdown. My system is powered by an >> UPS, but once in a year due to maintenance on the power supply it may >> happen that there is need to shutdown the system, or in case of blackout >> with a long time. How is it possible to completely shutdown the cluster >> by >> UPS command ? > > i believe shutting down rgmanager on every node will do the trick. or > else, shutting down cman should work too :) > > enjoy, > johannes > > -- > Linux-cluster mailing list > Linux-cluster@xxxxxxxxxx > https://www.redhat.com/mailman/listinfo/linux-cluster > -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
