Quote:
Originally Posted by
LoLo92
Actually, in my low-budget Customer environnement, this very HACMP cluster is only configured and used when needed
What do you mean by that? The whole point of a cluster is high-availability. If one of the nodes break the application still runs. If you know in advance when your node breaks you don't a cluster at all (although i don't believe such astute foretelling skills exist).
Quote:
Originally Posted by
LoLo92
that's why boths nodes are UNMANAGED for instance.
I don't understand this. "nodes" are the systems taking part in the cluster. They cannot be "unmanaged". They can only have their cluster services started ("joined the cluster") or not.
"Unmanaged" is a state only a
resource group can be in.
Quote:
Originally Posted by
LoLo92
And what risks you mentioned above could happended when using LVM commands instead of CSPOC ones ?
I thought i described that in pretty detail: you have a cluster for the situations where something has (quite drastically) gone wrong. To make it possible that filesystems, volumes, etc. are taken over safely and started on the other node they share the information about how these FSes, LVs, etc. are built and in which state exactly they are right now. If you make changes to a LV (like increasing its size, etc.) and use normal LVM commands this information will not be propagated to the other nodes because these commands are not cluster-aware. If you use the respective CSPOC commands which indeed are cluster-aware they will do the same as the normal LVM commands but also use the clusters communication services (RSCT) to propagate this changed information to the other nodes immediately.
Again, you can get away with using "learning imports" on the other nodes to make the information consistent again, but why not just use the cluster commands, which do that automatically?
I hope this helps.
bakunin