On 2018-02-13 05:46 AM, Maxim wrote: > 12.02.2018 19:31, Digimer пишет: >> Without fencing, all bets are off. Please enable it and see if the >> issue remains > Seems, i know [in theory] about the fencing ability and its importance > (although I've never configured it so far). > But i don't undestand how it would help in the situtions of the hard > reboot/shutdown.
An availability cluster's job is to keep things running. To do this, there must be coordination between the nodes (otherwise, just run things everywhere and be done with it). Thus, when a node stops responding, it is critical that the lost node be put into a known state. If you allow assumptions to be made, you will eventually assume wrong. That could have consequences as "minor" as confusing switches/routers to as devastating as corrupted data. Fencing is not meant to speed up recovery, it is critical to ensuring recovery works at all. This is a common confusion (and people often mistakenly think that quorum is how you avoid this, which is incorrect). There is no replacement for fencing; You need it in any availability system. Without it, it is like driving without a seat-belt. https://www.alteeve.com/w/The_2-Node_Myth >> Changing EL6 to corosync 2 pushes further into uncharted waters. EL6 >> should be using the cman pluging with corosync 1. May I ask why you >> don't use EL7 if you want such a recent stack? > For historical reasons. Let's say so. I've another software that built > for RHEL 6 like OS and have to be installed on the cluster node. > EL 7 stack is already not so recent, but it's one the most stable and > least vulnearable, i suppose. And i understand the risks. > I will update pcs to the latest version when i find a bit of free time. > _______________________________________________ > Users mailing list: Users@clusterlabs.org > http://lists.clusterlabs.org/mailman/listinfo/users > > Project Home: http://www.clusterlabs.org > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf > Bugs: http://bugs.clusterlabs.org -- Digimer Papers and Projects: https://alteeve.com/w/ "I am, somehow, less interested in the weight and convolutions of Einstein’s brain than in the near certainty that people of equal talent have lived and died in cotton fields and sweatshops." - Stephen Jay Gould _______________________________________________ Users mailing list: Users@clusterlabs.org http://lists.clusterlabs.org/mailman/listinfo/users Project Home: http://www.clusterlabs.org Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf Bugs: http://bugs.clusterlabs.org