Vu Pham wrote: > > Chen Ming wrote: >> Hi, >> >> I setup two cluster in same subnet, using the same name, it seems the >> later cluster can not startup. I try to start cman but failed. My >> environment is RHEL 5.3. >> >> My question: Is it possible to use the same cluster name in same subnet? >> > > From the man page of cman > ----------------- > Cluster ID > The cluster ID number is used to isolate clusters in the same > subnet. > Usually it is generated from a hash of the cluster name, but it > can be > overridden here if you feel the need. Sometimes cluster names > can hash > to the same ID. > > <cman cluster_id="669"> > </cman> > ----------------- > > So I think you either have to use different names or to explicitly > specify different cluster_id. > > But why do you have to have the same cluster name in the first place ? Bear in mind that using the same cluster name is highly dangerous if you are using GFS with storage that is shared between the clusters. GFS checks the cluster name before mounting and if it matches the current cluster assumes it's OK to carry on. If two clusters have the same name then that means two independent clusters could mount the same GFS volume. The result of that would be a totally corrupted filesystem. Chrissie -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
