12.07.2013, 09:15, "Digimer" <li...@alteeve.ca>: > On 12/07/13 00:59, Andrey Groshev wrote: > >> 11.07.2013, 18:48, "Digimer" <li...@alteeve.ca>: >>> You need fencing. Specifically, cman blocks when a fence is called and >>> won't unblock until it's told that a fence completed successfully. >>> Configure cluster.conf to use 'fence_pcmk', which tells cman to pass >>> fence requests to pacemaker, and then configure (and test!) stonith in >>> pacemaker. >>> >>> If you have just two nodes, be sure to also set '<cman two_node="1" >>> expected_votes="1" />'. >>> >>> digime >>> >>> On 11/07/13 09:35, Andrey Groshev wrote: >> I understand that it may be correct to do so... >> But why so difficult? >> Assume, I make a small НА cluster in my garage. >> And, I not have a managed switch or managed UPS. >> I can not corrupt the data. >> I just need to returning node as soon as possible started responding. > > First, fencing is not difficult, it's just one of the parts of > clustering to learn. Second, the cluster software has no concept of > "unimportant cluster". It treats every cluster as enterprise class. > Third, if a service can run on both nodes without coordination with one > another, then you don't need the cluster stack at all. > > Assuming you actually need to keep the service on one node or the other, > you need to have a way to make sure the "lost" node really is lost. You > are not allowed to make assumptions. "The only thing you know if what > you don't know". Fencing puts a node in an unknown state (disconnected? > frozen? crashed? blown to pieces?) and puts it into a known state, > "off". This ensures the service can never run on both nodes at the same > time. > > -- > Digimer > Papers and Projects: https://alteeve.ca/w/ > What if the cure for cancer is trapped in the mind of a person without > access to education?
Well, without a truly fence devices, I must use fence_pcmk? _______________________________________________ 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
