There is a subtle yet important difference between real time usage vs the allocated view of cloudstack. Allocated capacity refers to the resources reserved by MS whereas real time usage as the name refers is the actual usage (So for storage it is analogous to "df -h" (Linux command)).
Example MS has the following configuration : 2GB RAM, 2GHZ CPU, 10GB storage.
Lets say you choose a service offering of 1GB RAM, 1GHZ CPU and 5gb disk for deploying a vm, MS then reserves these capacities from its physical resources exclusively for this vm. While the vm's "actual usage" might be significantly less (say .1gb RAM , 128MHZ CPU and 1 gb storage) than the allocated(reserved) capacity. Assuming this to be the only vm in the system, the dashboard would display the following values.
Allocated RAM - 1/2 (50%)
Allocated CPU - 1/2 (50%)
Allocated Storage - 5/10 (50%)
Storage Used - 1/10 (10%) (analogous to "df -h" (Linux command))
*Dashboard view is updated real time for cpu and ram and every 5 mins (capacity.check.period) for allocated storage. For real time storage we update it every minute.