On Wed, Jul 21, 2021 at 3:55 PM Ulrich Windl <ulrich.wi...@rz.uni-regensburg.de> wrote: > > Hi! > > Maybe someone feels motivated to write some article comparing the concepts > * split brain > * quorum > * fencing >
Yet another one? Using your own reply "search is free". https://techthoughts.typepad.com/managing_computers/2007/10/split-brain-quo.html > There are eight possible states that I tried to illustrate on the attached > sketch (S="Split Brain", "Q=Quorum, F=Fencing). > > ;-) > > Regards, > Ulrich > > > >>> Andrei Borzenkov 21.07.2021, 07:52 >>> > > On 21.07.2021 07:28, Strahil Nikolov via Users wrote: > > Hi, > > consider using a 3rd system as a Q disk. > > What was not clear in "Quorum is a different concept and doesn't remove > the need for fencing"? > > > Also, you can use iscsi from that node as a SBD device, so you will have > > proper fencing .If you don't have a hardware watchdog device, you can use > > softdog kernel module for that. > > Best Regards,Strahil Nikolov > > > > > > On Wed, Jul 21, 2021 at 1:45, Digimer<li...@alteeve.ca> wrote: On > > 2021-07-20 6:04 p.m., john tillman wrote: > >> Greetings, > >> > >> Is it possible to configure a two node cluster (pacemaker 2.0) without > >> fencing and avoid split brain? > > > > No. > > > >> I was hoping there was a way to use a 3rd node's ip address, like from a > >> network switch, as a tie breaker to provide quorum. A simple successful > >> ping would do it. > > > > Quorum is a different concept and doesn't remove the need for fencing. > > > >> I realize that this 'ping' approach is not the bullet proof solution that > >> fencing would provide. However, it may be an improvement over two nodes > >> alone. > > > > It would be, at best, a false sense of security. > > > >> Is there a configuration like that already? Any other ideas? > >> > >> Pointers to useful documents/discussions on avoiding split brain with two > >> node clusters would be welcome. > > > > https://www.alteeve.com/w/The_2-Node_Myth > > > > (note: currently throwing a cert error related to the let's encrypt > > issue, should be cleared up soon). > > > > > > _______________________________________________ > > Manage your subscription: > > https://lists.clusterlabs.org/mailman/listinfo/users > > > > ClusterLabs home: https://www.clusterlabs.org/ > > > > _______________________________________________ > Manage your subscription: > https://lists.clusterlabs.org/mailman/listinfo/users > > ClusterLabs home: https://www.clusterlabs.org/ > > _______________________________________________ > Manage your subscription: > https://lists.clusterlabs.org/mailman/listinfo/users > > ClusterLabs home: https://www.clusterlabs.org/ _______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
