A cloud oversubscription system comprising an overload detector configured to model a time series of data of at least one virtual machine on a host as a vector-valued stochastic process including at least one model parameter, the overload detector communicating with an inventory database, the overload detector configured to obtain an availability requirement for each of the at least one virtual machine; a model parameter estimator communicating with the overload detector, the model parameter estimator communicating with a database containing resource measurement data for at least one virtual machine on a host at a selected time interval, the model parameter estimator is configured to estimate the at least one model parameter from the resource measurement data; a loading assessment module communicating with the model parameter module to obtain the at least one model parameter for each of the at least one host running at least one virtual machine and determine a probability of overload based on the at least one model parameter, wherein the loading assessment module communicates the probability of overload to the overload detector; wherein the overload detector compares the probability of overload to the availability requirement to identify a probable overload condition value; and wherein the overload detector communicates the probable overload condition value to a recommender, wherein the recommender generates an alert when the overload condition value exceeds the service level agreement requirements for any of the at least one virtual machine.