In cloud computing, virtual machine (VM) placement is a critical operation performed during VM migration. It entails selecting the optimal physical machine (PM) to host VMs, directly influencing data center performance, resource utilization, and power consumption. Various VM placement schemes have been devised to improve different aspects of data center operations and VM executions.

What does a Virtual Machine do?

A virtual machine allows you to run one operating system inside another – hence the term 'virtual.' However, not all VMs are configured within an OS on your computer; they could also be remotely assembled unseen and unheard. While you can perform regular tasks on a virtual machine, you cannot physically interact with it.

So, why are virtual machines necessary? Several factors contribute to this:

• Virtualization saves costs by requiring only a fraction of the hardware used in traditional setups.
• It saves physical space and reduces maintenance efforts.
• Less hardware means fewer maintenance costs and little management overhead.

While VMs may continue to function even if not optimally placed in the cloud, their performance and uptime may suffer, impacting user experience.

Why should you consider VM placement?

• Improves overall performance characteristics of the system.
• Reduces energy consumption and cooling costs.
• Enhances resource utilization by efficiently distributing workloads.

VM placement is an ongoing process in cloud computing, where network engineers periodically assess VMs to determine if migration to another server is necessary.

Is a virtual machine secure?

Every virtual machine consists of two components: the host and the guest. These components are separated, ensuring that malware in one component cannot affect the other. However, the VM placement problem (VMPP) is inherently dynamic, with new VMs arriving, older ones leaving, or changing their resource requirements.

Despite specifying RAM, CPU, and storage requirements in advance, occasional surges in utilization may occur, which could affect efficient VM placement. VMPP algorithms need to be invoked during each rescheduling, ensuring minimal disruption and cost during migration.