On Wed, 2010-05-05 at 16:21 +0200, Dejan Muhamedagic wrote: > rackpdu also works over the network. The lights-out device has > its own network interface. Presumably both should be connected to > some management network. Where's the difference?
The difference is in redundancy. Both radkpdu and ipmilan use a network, but it's not the SAME network. So using both doesn't avoid all points of failure, but it avoids a NIC or cable being a *single* point of failure. > it is unlikely that something would happen that causes > > only one of the servers to completely lose power other than human error > > (possibly a motherboard failure as well?) > > That's an interesting question. Perhaps the server vendor can > tell. I think there will always be hardware failure modes that would cause the server to be non-functional and the ipmilan stonith to fail. I do understand that these situations would be very rare. It isn't like this is a show-stopper problem. But I am still looking to see if it can be insulated against. > > You can have more than one stonith resource and they'll be tried > in a round-robin fashion until one succeeds. Yes. This is what I have now with the ipmilan first and meatware second. I've tested this. Brute force killing of heartbeat does result in an ipmilan stonith. Powering down one of the servers causes the resources running on that server to be in a non-running state, because then the ipmilan stonith will fail, but running the meatclient program can force the remaining server to take over once I verify that the power to the other server is really really gone. I would manually shut off outlets on the PDU to ensure it, but at least all of that can be done remotely using the server that is still up. Better still, of course, would be to have the remaining server shut off the outlets and take over resources automatically, which is what I'm aiming for here. > The plugin picks the outlet in one of the two ways: > > - from the device itself, provided that the outlet name matches > the node name > - from the external file which specifies the mapping I expect that allowing multiple PDU/outlet combinations to be specified in the config file is the only way to do this. > > I can help with modifying the plugin if you'll do the testing. I'd be more than happy to do some testing. That's what the test cluster is for. --Greg _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
