2) The real problem is that unless the database is co-located with the
Xymon server, then your monitoring suddenly becomes dependant on
a remote database-server. So what happens if your database server loses
the network connection to the Xymon server ? You won't get any alerts
from Xymon, because it has no data available to generate alerts from.
It's the same reason that has kept me from using SAN storage for my
production Xymon server at work. Much too complex for my taste, far
too many ways it can break.
Interesting that you should mention that, because our Xymon installation has
all of the /var/hobbit/data stuff stored on a SAN mount. This has worked
out fairly well for us (though we did have an intermittent issue for a few
months that eventually got straightened out).
However, I'm working on implementing an HA solution for Hobbit using
LinuxHA, and I think we'll be moving from SAN-based storage to local
storage, using DRBD for replication between the two nodes.