Paul,
In regards to monitoring storage consumption for a group, you can use the Group Summary report (see attachment). It will show how much capacity has been allocated to the resource group, and how much of that capacity has been consumed. You can also run the groups-bytes-usage report to view all groups at once.
C:\> dfm report view groups-bytes-usage
Object ID Group Status Contents Used Total Used (%)
--------- ------------------ ------- ---------- ------- -------- --------
234 Aggregates Warning 7 volumes 1289056 2865152 45.0
219 Configuration Mgmt Warning 22 volumes 5844496 44086524 13.3
233 LUNs Normal 1 volume 1163348 2097152 55.5
330 My LUNS Normal 2 volumes 1792256 3145728 57.0
218 Oracle DB Normal 0 volumes
210 Site-A Warning 7 volumes 1289056 2865152 45.0
211 Site-B Normal 7 volumes 1606900 8517224 18.9
212 Site-C DR Location Normal 8 volumes 2948540 32704148 9.0
305 vFiler Config Mgmt Normal 5 volumes 1772 266240 0.7
217 VMware Datastores Normal 0 volumes
235 Volumes and Qtrees Warning 2 volumes 1287640 2260992 57.0
However, to the best of my knowledge, there is no functionality for creating an alarm on a group's storage consumption. You are limited to capacity thresholds for physical objects (aggregates) or logical objects (volumes, qtrees and LUNs). That being said, there is nothing stopping you from writing a script to notify you when a group exceeds a certain capacity utilization. Ops Mgr can provide all of the information you need. The script just needs to parse the information, compare it against some type of threshold, and send an e-mail if necessary.
