>>> Dimitri Maziuk <dmaz...@bmrb.wisc.edu> schrieb am 09.09.2016 um 02:17 in Nachricht <72d90bbe-1eb8-f2d8-e7d4-43e0a19b6...@bmrb.wisc.edu>: > On 09/08/2016 06:33 PM, Digimer wrote: > >> With 'fencing resource-and-stonith;' and a {un,}fence-handler set, DRBD >> will block when the peer is lost until the fence handler script returns >> indicating the peer was fenced/stonithed. In this way, the secondary >> WON'T promote to Primary while the peer is still Primary. It will only >> promote AFTER confirmation that the old Primary is gone. Thus, no >> split-brain. > > In 7 or 8 years of running several DRBD pairs I had split brain about 5 > times and at least 2 of them were because I tugged on the crosslink > cable while mucking around the back of the rack. Maybe if you run a > zillion of stacked active-active resources on a 100-node cluster DRBD > split brain becomes a real problem, from where I'm sitting stonith'ing > DRBD nodes is a solution in search of a problem.
I think the problem is that people using DRBD don't have shared storage, thus cannot use SBD for fencing (i.e. they use (just as DRBD does) network-based fencing). SO if the network fails, both things fail: DRBD sync and fencing. I think a working solution should have highly-available independent channels for DRBD and fencing. Regards, Ulrich > > -- > Dimitri Maziuk > Programmer/sysadmin > BioMagResBank, UW-Madison -- http://www.bmrb.wisc.edu _______________________________________________ Users mailing list: Users@clusterlabs.org http://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