Host-level aggregation

[edzheng]

Cacti could aggregate numeric data by time, e.g. aggregate 5-min data to 1-hour average.
Besides that, is it possible to use cacti to aggregate data from host level to cluster/hostgroup level? e.g. I have the 1-hour average CPU utilization for each host, but my boss wants to see a graph of 1-hour average CPU utilization for all linux boxes and all solaris boxes, so that he could compare the utilization of the two groups of the hosts.

If there's no built in functionality, what's the possible workaround?