Hi Lars, Hi Lars!
> You are exercising complete cluster communication loss. > Which is cluster split brain. Correct, yes. > If you are specifically exercising cluster split brain, why are you surprised > that you get exactly that? Because ping(d) is supposed to keep ressources from starting on nodes which are not properly connected to the network. Thus: Still split brain, but no possibility for concurrent (and possibly damaging) access to resources. > You need to reduce the probability to run into complete communication loss, by > - using multiple communication links. There will be *one* dedicated (mpls) line between the two sites. No possibility for any "real" redundant links; honestly, believe me. The only way would be the usage of GSM modems or other wireless links, which is not possible for several other reasons (which I can't discuss here). > - using a real quorum > (there is no quorum in a two node failover cluster) Yes, and there is no proper way to use DRBD in a three node cluster. Until then (unless we have a dedicated, replicated, shared storage, which we don't have, unfortunately), it's a two node cluster or nothing. This - inevitably - leads to the need for an "external quorum", and ping(d) seems to do that, as far as I understood the docs. Please correct me if I'm wrong. > You may want to still guard against the ugly effects of cluster split brain, > by > - implementing stonith > - configuring stonith properly There's no proper way for doing stonith in a split-site scenario, besides "meatware". If the link is down between the two sites, you won't be able to access any ILO, UPS or other stonith device. > - additionally configuring fencing in DRBD Yes, I'm going to try that. Still: Please tell me if ping(d) is behaving properly or if it isn't. You've seen my configuration. I think it should work (and, indeed, it did a while ago; it could well be that we misconfigured something after that, but I just can't find what it is... THANKS, Andreas -- : Lars Ellenberg : LINBIT | Your Way to High Availability : DRBD/HA support and consulting http://www.linbit.com DRBD® and LINBIT® are registered trademarks of LINBIT, Austria. _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems ------------------------ CONET Solutions GmbH, Theodor-Heuss-Allee 19, 53773 Hennef. Registergericht/Registration Court: Amtsgericht Siegburg (HRB Nr. 9136) Geschäftsführer/Managing Directors: Jürgen Zender (Sprecher/Chairman), Anke Höfer _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
