In VMWare vSphere, how can I set and track the
monthly bandwidth usage of each guest? I need to reduce the network speed when bandwidth
90% or so.
What are my
Really depends on what you're trying to do. If you want to simply restrict throughput, you can modify the port group traffic shaping to limit outgoing bandwidth to whatever you want your peak to be. It won't work on inbound traffic though, and its per port group. So if you have two port groups set to 90%, it still possible for the combination of the two to exceed 90%.
With a distributed switch, the above scenario potentially becomes a little better because you could using NIOC to limit VM traffic, rather than doing it per port group, but again, only outbound.
If you goal is, how can i trend the data over a month for reporting purposes, and you have vCenter, you can increase your statistics logging to keep more granular data for a longer period of time, but that can blow up your DB really quick and causing performance issues. In this case, it's much better to use a monitoring application and trend your data through it. Something like a Solarwinds or LogicMonitor.