There are 3 possibilities for vlan tagging on a ESX host. The following description is only for the VST mode. The other 2 (EST and VGT mode) are not described in the following procedure:
Within Server 2008 it is possible to limit a user a specific percentage of CPU Time.
Lets assume there is a Backup Service Account. This account makes every night a backup. The creation of a backup is time consuming process (depends on amount of data) and there is a requirement from the business that it may not prohibit the business from functioning.