Motivated by current trends in cloud computing, the authors explain study a version of the generalized assignment problem where a set of virtual processors has to be implemented by a set of identical processors. For literature consistency they say that a set of Virtual Machines (VMs) is assigned to a set of Physical Machines (PMs). The optimization criteria is to minimize the power consumed by all the PMs. They term the problem Virtual Machine Assignment (VMA). Crucial differences with previous work include a variable number of PMs, that the VMs cannot be implemented fractionally (i.e., each VM must be assigned to exactly one PM), and a parametric minimum power consumption for each active PM.