How do virtual machines manage system resources?

Virtual machines manage system resources by allocating and isolating them for each virtual environment.

Virtual machines (VMs) are software emulations of physical computers. They run an operating system and applications just like a physical computer. VMs get their resources - such as CPU, RAM, and storage - from the host machine, which is the physical computer on which the virtualisation software runs. The virtualisation software, or hypervisor, is responsible for managing these resources.

The hypervisor allocates resources to each VM based on its needs and the overall resources available on the host machine. This allocation is flexible and can be adjusted as the needs of the VM change. For example, if a VM is running a resource-intensive application, the hypervisor can allocate more CPU or RAM to it. Conversely, if a VM is idle, the hypervisor can reallocate its resources to other VMs that need them.

In addition to allocating resources, the hypervisor also isolates the resources of each VM. This means that each VM operates independently of the others and does not have access to their resources. This isolation is crucial for security and stability. If one VM crashes or is compromised, the others are not affected because they do not share resources.

The hypervisor also manages the storage resources for each VM. Each VM has its own virtual hard drive, which is a file or set of files on the host machine's physical hard drive. The hypervisor manages the size and location of these files. It can also create snapshots of the VM's hard drive, which are point-in-time copies that can be used to restore the VM to a previous state.

In summary, virtual machines manage system resources through the hypervisor, which allocates and isolates resources for each VM based on its needs and the overall resources available on the host machine. This management ensures that each VM has the resources it needs to run its operating system and applications, while also maintaining security and stability.