Quote:
Originally Posted by
qiulang
BTW my original question was "what is the benefit of running HACMP for [...]
It seems to me like your real problem is adapting to the terminology of HACMP, in this case namely the term "resource group".
Suppose the classical case with no HACMP involved: you have a system where an application runs. The application has some disks holding its data and the data are all in a volume group. Further you have some network adapter (an IP adress) over which the users know they can contact the application.
Now lets abstract from this concept: what do we need to transfer to another system to transfer the task of serving the application? Answer: the volume group with the data, the IP adress the users expect, some start/stop mechanisms for the application - thats it. Exactly this is what is called a resource group. It is a data structure inside the HACMP configuration which binds together exactly these things.
Resource groups always reside on one node of a cluster and can be transferred to another node in case the active node dies. This is what shockneck has tried to explain to you in the active-active configuration: suppose your default would be a node A with some resource group A' operative and a node B with a RG B' operative. If node A dies, RG A' is being transferred to node B which will run both, vice versa, if node B dies.
Yes, "mutual takeover" is just another name for this mechanism. But however you call it, it helps to picture the RGs moving around on the nodes in case of hardware outages.
I hope this helps.
bakunin