Gregory Farnum wrote: >> If: (more clear with a schema in the head ;)) >> >> 1. mon.1 and mon.2 can talk together (in dc1) and can talk with mon.5 (via the VPN) >> but can't talk with mon.3 and mon.4 (in dc2) >> 2. mon.3 and mon.4 can talk together (in dc2) and can talk with mon.5 (via the VPN) >> but can't talk with mon.1 and mon.2 (in dc1) >> 3. mon.5 can talk with mon.1, mon.2, mon.3, mon.4 and mon.5 >> >> is the quorum reached? If yes, which is the quorum? > > Yes, you should get a quorum as mon.5 will vote for one datacenter or > the other. Which one it chooses will depend on which monitor has the > "lowest" IP address (I think, or maybe just the monitor IDs or > something? Anyway, it's a consistent ordering). Under no circumstances > whatsoever will mon.5 help each datacenter create their own quorums at > the same time. The other data center will just be out of luck and > unable to do anything. Ah ok, interesting information, finally I would bet on a no-quorum state, but I was wrong. > Although it's possible that the formed quorum won't be very stable > since the out-of-quorum monitors will probably keep trying to form a > quorum and that might make mon.5 unhappy. Ok, so in fact the idea of an external monitor in WAN is a very bad idea. ;) > You should test what happens with that kind of net split. :) Currently I can't. In fact, if I have asked the question it's because we are thinking about some expansion and purchase of servers but currently we are just thinking. Thanks Greg for the answer. -- François Lafont _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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