Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Matteo Campana wrote: > Hi Lars and all the guys in ML :). > My problem is to understand the behaviur of my HA system: I have read > in the documentation about heartbeat that at least 2 channels of > communication between 2 nodes are required to preserve the system from > the "split brain" problem (in my system I have 1 ethernet + 1 serial). > But....in my tests I see however that DRBD says the "infamous" :) > message "split-brain detected" ecc.. . > My test: > > * I disconnect primary node from the ethernet > * secondary ----> primary (ok) > If you only disconnected the ethernet interface and this happened, apparently your serial heartbeat is not working. Because if it was, heartbeat would understand that this is a communications channel failure, not node failure so it should not migrate resources If you disconnected both the serial and the ethernet, you have induced an artificial split-brain situation. Both heartbeats have no way of knowing the other is still alive. You can verify this, if at this moment on both servers /proc/drbd claims to be ``Primary/Unknown'' See this: http://www.linux-ha.org/GettingStarted I do not know if/how STONITH could have helped in this situation, but you might want to check on that. > * I reconnect primary > * secondary still remain primary (ok for my config) > * the problem is that the two nodes are standalone and not > re-syncronize theirs drbd partition. > > DRBD does not use also the serial channel in order to communicate > between the nodes? > And if does not, there is a lack of documentation :) > > > Regards, > Matteo. > > -- > *Ing. Matteo Campana > System Engineer > > Klarya s.r.l.* > > Sede Operativa: > Via Agnini 47 - 41037 Mirandola (MO) > > Tel +39 0535 27325 > > Fax +39 0535 610050 > > Mob +39 320 4258536 > > Sede Legale: > Via Salgari, 17 - 41100 Modena > > Tel +39 059 821332 Fax +39 059 821492 > > email: matteo.campana at klarya.it > > web: www.klarya.it > > > * > **Open Source IP Communications* > __________________________________________________ > ------------------------------------------------------------------------ > > _______________________________________________ > drbd-user mailing list > drbd-user at lists.linbit.com > http://lists.linbit.com/mailman/listinfo/drbd-user >