IOPS / Througput as QUOTABLE items
Besides the amount of storage / amounts of disks, one of the most valuable resources in a (virtualized) environment are IOPS (and througput to a lesser extent). Being able to limit these one way or the other makes a lot of sense. Setting limits on DISKS / VM's (issue #5510) will help, but is not enough. It should be possible to limit (and bill) IOPS:
1) IOPS / throughput quota per GROUP/USER
2) IOPS / throughput quota per DATASTORE
Ad 2) datastores that have to provide the IOPS / Throughput have limits as well. By specifying limits per datastore, overcommiting IOPS per datastore can be prohibited, or at least be configured.