  Cloud computing datacenters provide millions of virtual machines in actual
cloud markets. In this context, Virtual Machine Placement (VMP) is one of the
most challenging problems in cloud infrastructure management, considering the
large number of possible optimization criteria and different formulations that
could be studied. Considering the on-demand model of cloud computing, the VMP
problem should be solved dynamically to efficiently attend typical workload of
modern applications. This work proposes a taxonomy in order to understand
possible challenges for Cloud Service Providers (CSPs) in dynamic environments,
based on the most relevant dynamic parameters studied so far in the VMP
literature. Based on the proposed taxonomy, several unexplored environments
have been identified. To further study those research opportunities, sample
workload traces for each particular environment are required; therefore, basic
examples illustrate a preliminary work on dynamic workload trace generation.
