AIX

OK, but: how often do you change the network in your environment? If this was a one-time occasion it is probably best to leave it as it is. Like zaxxon said already (words to this effect): if it isn't broken, then don't fix it.


It is good practice to have at least one non-IP connection (i.e. disk heartbeat or even the old-style serial connection) to avoid this. But even if it happens: this is what HACMP is expected to do. If you really have a need to change this behavior this begs the question if HACMP/PowerHA is the right tool for your needs.

This is also to be expected. You don't want to get a "split-brain condition", that is: two hosts both believing they are (or should be) primary. You simply power on your once-primary host, start the cluster services, do an "extended cluster verification" (if you are really paranoid, which is a good trait for a systems administrator) and after successfully verfying the cluster do a resource-group move. Then you have the status quo ante again.

Btw., according to this (rather ancient) HACMP 4.4 document the trip interval is for configuring the DMS (Dead-Man-Switch). If a cluster node doesn't give answer for this amount of time (in seconds) the other node considers it to be dead and not only takes over the resources but also will initiate a shutdown if the node comes back.

Keeping this in mind there can't be any sensible "default" with which to stick- You will have to tune this to your needs. It will always be a trade-off between security - if a node becomes unresponsive you want to take it over as fast as possible - and serviceability - you don't want unnecessary takeovers. What your most sensible trade-off-value should be can't be determined without extensive knowledge of your sites necessities and the intricacies of your environment.

You're officially YOYO (you're on your own).

I hope this helps.

bakunin