Which of the following is true for virtual server clusters ? on-demand scalability no overhead of virtualization run on top of physical servers VM placement decisions can impact its performance Which of the following factors can possibly affect VM placement decisions in a cloud datacenter ? size of a VM in terms of number of VCPUS and amount of memory user-defined VM affinity rules power constraints in datacenter racks O Guest OS running on the VM Which of the following factors can possibly affect VM placement decisions in a cloud datacenter ? size of a VM in terms of number of VCPUS and amount of memory user-defined VM affinity rules power constraints in datacenter racks O Guest OS running on the VM VM live migration is suitable for which of the following scenarios ? O load balancing among datacenter servers dynamic power management in a cloud datacenter regular maintenance and upgrade of servers in a cloud datacenter O migrating a VM between cloud datacenters